for Journals by Title or ISSN
for Articles by Keywords
help
  Subjects -> BIOLOGY (Total: 2691 journals)
    - BIOCHEMISTRY (207 journals)
    - BIOENGINEERING (77 journals)
    - BIOLOGY (1342 journals)
    - BIOPHYSICS (45 journals)
    - BIOTECHNOLOGY (152 journals)
    - BOTANY (205 journals)
    - CYTOLOGY AND HISTOLOGY (24 journals)
    - ENTOMOLOGY (54 journals)
    - GENETICS (141 journals)
    - MICROBIOLOGY (224 journals)
    - MICROSCOPY (9 journals)
    - ORNITHOLOGY (23 journals)
    - PHYSIOLOGY (66 journals)
    - ZOOLOGY (122 journals)

BIOLOGY (1342 journals)            First | 7 8 9 10 11 12 13 14     

The end of the list has been reached. Please navigate to previous pages.

  First | 7 8 9 10 11 12 13 14     

Journal Cover Journal of Applied Ichthyology
   [8 followers]  Follow    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 0175-8659 - ISSN (Online) 1439-0426
     Published by John Wiley and Sons Homepage  [1603 journals]   [SJR: 0.427]   [H-I: 33]
  • A revised checklist of Cape Verde Islands sea fishes
    • Authors: R. Hanel; H.‐C. John
      Pages: n/a - n/a
      Abstract: During ichthyological research and teaching activities in the Cape Verde Archipelago, the authors noticed that the readily available inventories of its sea fishes underrepresented the mesopelagic species, contrary to an older Spanish list, which regrettably remained widely unknown. These inventories were compared, revised, combined and commented on, plus a multitude of individual descriptions, survey reports, biogeographical treatises, and unpublished data were put in a checklist. From the resulting list of 1046 names thus far reported, 779 species are supported by records, respectively, their general zoogeography. Another 29 records need confirmation. Seventeen (in the literature, up to 20) species are believed to be endemic. The list comprises 91 first records, plus many earlier records from previously disregarded literature. Seventy‐five other names are erroneous either by synonym, misidentification, or misspelling. In 64 cases earlier listings referred to an erroneous geographical location. The number of recorded species will likely increase with future ichthyological research. The ichthyofauna of the Cape Verde Islands is composed mainly of widely distributed species, plus those from the Guinean Region, a few endemics, several amphi‐Atlantic species, as well as shore fishes from the NW African coast.
      PubDate: 2014-12-19T04:53:30.268245-05:
      DOI: 10.1111/jai.12621
       
  • Length–weight relationships of 20 fish species from Pahang River,
           Maran district, Pahang, Malaysia
    • Authors: A. R. Zulkafli; M. N. A. Amal, S. Shohaimi, A. Mustafa, A. H. Ghani, S. Hashim, M. I. Anuar, M. P. Hasfairi
      Pages: n/a - n/a
      Abstract: This study reports the length–weight relationships (LWR) of 20 fish species from the Pahang River, Maran district, Pahang, Malaysia. The river supplies fishes mainly for local consumption and is a principal body of water for freshwater aquaculture in Malaysia. A total of 12 LWR of fishes were unknown to FishBase, and five new maximum lengths of fishes were identified from the study.
      PubDate: 2014-12-19T04:37:38.761927-05:
      DOI: 10.1111/jai.12666
       
  • Effects of tank colour on feed intake, specific growth rate, growth
           efficiency and some physiological parameters of rainbow trout
           (Oncorhynchus mykiss Walbaum, 1792)
    • Authors: S. Rahnama; M. S. Heydarnejad, M. Parto
      Pages: n/a - n/a
      PubDate: 2014-12-19T04:31:19.815667-05:
      DOI: 10.1111/jai.12664
       
  • Larval growth of two species of lanternfish at nearshore waters from an
           upwelling zone based on otolith microstructure analyses
    • Authors: M. F. Landaeta; J. E. Contreras, C. A. Bustos, G. Muñoz
      Pages: n/a - n/a
      Abstract: Larval growth and hatching days of lanternfishes Diogenichthys laternatus and Myctophum nitidulum (Myctophidae) collected in September 2012 in nearshore waters (
      PubDate: 2014-12-19T04:26:25.322695-05:
      DOI: 10.1111/jai.12639
       
  • Effects of different food on growth and survival of first‐feeding
           taimen Hucho taimen (Pallas, 1773) larvae
    • Authors: C.‐A. Wang; J.‐Z. Ma, Q.‐Y. Xu, J.‐S. Yin, Z.‐G. Zhao, J.‐N. Li, L.‐S. Wang, L. Luo
      Pages: n/a - n/a
      Abstract: A study was conducted to compare growth and survival of Hucho taimen larvae from 21 to 76 days after hatch (DAH) fed one of three diets: formulated feed alone (group F); a co‐feeding diet of water fleas, tubifex and formulated feed (group C); or live food of water fleas and tubifex (group L), and to investigate the potential use of dietary L‐alanyl‐L‐glutamine (L‐AG) in larval taimen for a more nutritious starter diet. Triplicate groups of 5000 fish were randomly assigned to each aquarium provided with water from a flow‐through system, and fed to apparent satiation. The results show that larvae can feed efficiently on floating crumbled particles of formulated feed. Weight gain of larvae fed only formulated feed was significantly lower than other groups at 34 DAH (P 
      PubDate: 2014-12-19T04:25:52.048732-05:
      DOI: 10.1111/jai.12663
       
  • Population parameters of the fish fauna in a long‐established
           Amazonian reservoir (Amapá, Brazil)
    • Authors: J. C. Sá‐Oliveira; R. Angelini, V. J. Isaac‐Nahum
      Abstract: The present study focused on the fish fauna of the 44‐year‐old Coaracy Nunes reservoir in the northern Amazon basin, producing estimates of the growth constant (k), maximum and asymptotic body lengths and weights, natural mortality (M), the consumption/biomass ratio (QB) (intake of food by a group over a year), the Aspect ratio (Ar) of the caudal fin, growth performance (Φ), longevity, and trophic level for 45 fish species. Species collection was divided into eight sampling campaigns between May 2009 and July 2010. Gillnets were used in four of the sampling sites. The results revealed that (i) the most predominant species are Ageneiosus ucayalensis, Hemiodus unimaculatus, Serrasalmus gibbus and Geophagus proximus; (ii) small and medium‐sized fishes predominated in the community, characterized by high rates of growth and natural mortality, consistent with a predominance of r‐strategists; (iii) the body lengths of the detritivore species were similar to those of the piscivores, which are normally larger, but with higher growth rates, more similar to those recorded for the omnivores; (iv) consumption/biomass ratio (QB) × body length relationship is higher in the detritivores than in the omnivores and piscivores (which were similar to each other). Overall, the reservoir habitat appears to be advantageous to detritivorous fish species.
      PubDate: 2014-12-16T00:48:52.783068-05:
      DOI: 10.1111/jai.12667
       
  • Occurrence of Pseudocorynopoma heterandria Eigenmann, 1914 (Characidae) in
           Paraíba do Sul River Basin (Southeastern Brazil)
    • Authors: F. L. K. Salgado; B. F. Terra, G. S. Camilo, E. O. Silva, F. G. Araújo
      PubDate: 2014-12-15T06:56:46.386487-05:
      DOI: 10.1111/jai.12657
       
  • Age, growth and mortality of Lutjanus alexandrei in estuarine and coastal
           waters of the tropical south‐western Atlantic
    • Authors: A. Aschenbrenner; B. P. Ferreira
      Abstract: Otolith‐based methods were used to determine life history traits of the endemic Brazilian snapper (Lutjanus alexandrei) in estuarine and coastal environments in the south‐western Atlantic. Fishes were caught as juveniles inside mangrove‐bordered estuaries by traditional corral fisheries whereas adults were captured at sea using motorboats with trap and gill nets. Fish were sampled during landings and 331 otolith pairs were extracted from L. alexandrei. Inshore mangroves comprised individuals of 0–4 years (mean: 2 years), while individuals in deeper reef environments were older (range: 3–22; mean: 8 years), indicating an ontogenetic shift at approximately age 3 or 4. Edge analysis was used to validate the annual deposition in the otoliths, suggesting that opaque growth rings were formed between April and September. Age‐at‐length data were used to predict L. alexandrei growth rates using the von Bertalanffy growth model from where the parameters were calculated: L∞ = 31 cm, k = 0.24, t0 = −1.26, r2 = 0.97. Mortality rates were estimated for coastal habitats, with Z = 0.22 and S = 0.78 year−1, based on ages 7–17. Additionally, evidence of ontogenetic migration is provided by age and size structure.
      PubDate: 2014-12-15T06:56:37.256458-05:
      DOI: 10.1111/jai.12633
       
  • Length‐weight relationships for 55 freshwater fish species from the
           Iguatemi River, Upper Paraná River basin, Brazil
    • Authors: V. F. Batista‐Silva; D. Bailly, E. A. L. Kashiwaqui, M. C. F. Abelha, W. J. Graça
      Abstract: This study reports the length‐weight relationship estimatives (LWRs) for 55 fish species caught in the Iguatemi River drainage, Upper Paraná River Basin, Mato Grosso do Sul State, Brazil. The LWRs of 15 of the species are provided for the first time.
      PubDate: 2014-12-15T06:55:45.048588-05:
      DOI: 10.1111/jai.12654
       
  • Length–weight relationships and biological data on guayana
           pike‐conger Cynoponticus savanna (Bancroft, 1831)
    • Authors: J. A. Reis‐Filho; L. Specht
      Abstract: This study presents the first references available for Cynoponticus savanna length–weight relationships (LWR) as well as other biological information, based on its unique population in the South Atlantic Ocean, specifically, Todos os Santos Bay, on the Brazilian central coast. A total of 464 individuals were obtained from artisanal fishing landings between July 2012 and June 2013. Total lengths ranged from 14.5 to 139.6 cm. The length‐weight relationship was BW = 0.716 TL3.31. Length at first maturity (Lm) was 48.9 cm. Reproduction began gradually in May, reaching a peak around December, with most individuals completing reproduction by January. The gonadosomatic index (GSI) was highest in January (GSI = 0.21) and lowest in March (GSI = 0.024). The male index (GSI = 0.073) was lower than in females (GSI = 0.10) (P 
      PubDate: 2014-12-15T06:51:30.707136-05:
      DOI: 10.1111/jai.12662
       
  • First record of the new unisexual triploid form, one genome of Cobitis
           hankugensis and two genomes of Cobitis longicorpa from a wild population
           (Cobitidae, Teleostei), South Korea
    • Authors: M. H. Ko; S. W. Yoon, C. H. Kim, J. Y. Park
      Pages: n/a - n/a
      PubDate: 2014-12-10T02:26:39.285864-05:
      DOI: 10.1111/jai.12647
       
  • Improving nematode culture techniques and their effects on amino acid
           profile with considerations on production costs
    • Authors: B. H. Buck; J. Brüggemann, M. Hundt, A. A. Bischoff, B. Grote, S. Strieben, W. Hagen
      Pages: n/a - n/a
      Abstract: The purpose of this study was to investigate the effectiveness of 11 different culture media for production of the free‐living nematode Turbatrix aceti. Several other harvesting methods were tested in addition to mass production. A further focus was the investigation of amino acid alterations caused by the application of various media during the culture of T. aceti and two additional nematode species, Panagrellus redivivus and Caenorhabditis elegans. Finally, a cost analysis for the production of T. aceti was generated and its outcome compared to the production of conventional live feed organisms. Altogether 11 liquid culture media were tested for mass production of the nematode Turbatrix aceti using a minimum of effort in terms of labour and costs. Six harvesting methods, including filtration as well as active swimming of T. aceti were evaluated. Additional to the culture of T. aceti in four of the above‐mentioned media, the nematodes P. redivivus and C. elegans were cultured on two different solid media. Cost analysis for the production of T. aceti includes those of the media, the equipment, as well as the labour costs for culture and harvest. An average density of approx. 30 × 106 ± 8.13 × 106 nematodes L−1 was achieved for T. aceti. The most efficient method (20 μm filtration) allowed harvesting 85.3 ± 2.7% of the nematodes from the medium without disturbing the particles. Lowest efficiency was achieved by combining sedimentation and filtration, accomplishing a harvest of 42.1 ± 5.8%. The amino acid profile of all three nematode species turned out to be both stable and very similar. Amino acid enrichment had little effect. The costs for producing one million T. aceti individuals ranged between 5.39 and 6.19 €, where labour costs accounted for 73 to 84% of the total production costs. In conclusion, T. aceti appears to be very robust, easy to handle, as well as cheaper to cultivate compared to other live‐feed organisms. Therefore, its use in commercial aquaculture should be given future consideration.
      PubDate: 2014-12-10T00:06:03.5023-05:00
      DOI: 10.1111/jai.12645
       
  • A non‐native fish assemblage in geothermal waters of Romania
    • Authors: I. Sas‐Kovács; I. C. Telcean, S.‐D. Covaciu‐Marcov
      Pages: n/a - n/a
      PubDate: 2014-12-08T23:38:40.287378-05:
      DOI: 10.1111/jai.12652
       
  • Relationship between Fulton's condition factor and proximate body
           composition in three freshwater fish species
    • Authors: A. Mozsár; G. Boros, P. Sály, L. Antal, S. A. Nagy
      Abstract: Morphometric‐based condition indices are widely used to assess proximate body composition and, collaterally, feeding and living conditions of fish. However, the exact relationship between condition indices and proximate body composition of fish and its relatedness to life history traits and seasonality has yet to be fully explored. Therefore, the aim of this study was to examine how the Fulton's condition factor (K‐factor) is related to the chemical composition (i.e. lipid, protein, water and carbon content, and molar carbon : nitrogen ratio), length and gonadal development of fish, and how these relationships are influenced by gender and seasonality in three freshwater fish species: Amur sleeper (Perccottus glenii), pumpkinseed (Lepomis gibbosus) and rudd (Scardinius erythrophthalmus). It was found that the strength and direction of association between the K‐factor and proximate body composition can vary markedly among fish species. The K‐factor correlated positively with gonadal development in pumpkinseed and Amur sleeper, while no such relationship existed in rudd. Condition factor can be a reliable measure of lipid content; however, the relationship was stronger in species with higher and more variable lipid contents. Moreover, a striking and consistently negative linkage was found between the K‐factor and water content of the fish body, which corresponds to the findings of several other studies. In turn, any relationship between the K‐factor and the protein content of fish was not detected. Gender seemed to exert a negligible effect on the relationship between the K‐factor and proximate body composition, while seasonal variance was obvious in most relationships.
      PubDate: 2014-12-08T02:17:30.895627-05:
      DOI: 10.1111/jai.12658
       
  • Weight–length relationships of six endemic fish species of Greece
    • Authors: O. Petriki; D. C. Bobori
      Abstract: The weight–length relationships (WLRs) for six endemic fish species of Greece are presented here. All WLRs were highly significant (P 
      PubDate: 2014-12-08T02:17:07.718613-05:
      DOI: 10.1111/jai.12650
       
  • Length–weight relationships of 22 fish species from the East China
           Sea
    • Authors: M. Yagi; M. Yamada, M. Shimoda, J. Uchida, T. Kinoshita, K. Shimizu, N. Yamawaki, T. Aoshima, Y. Morii, H. Kanehara
      Abstract: Estimated length–weight relationships are presented for 22 commercially important marine fish species representing nine families, found in the East China Sea. A total of 2776 specimens were caught by otter trawl on the continental shelf in the East China Sea between 2009 and 2013. Information pertaining to length–weight relationships should lead to a better understanding of fish communities in the East China Sea.
      PubDate: 2014-12-08T02:16:47.496677-05:
      DOI: 10.1111/jai.12648
       
  • First record of Cephalopholis formosa (Shaw, 1812) (Persiformes:
           Serranidae) in the Persian Gulf
    • Authors: P. Tavakoli‐Kolour; S. Khatami, A. Barkhordari, A. Farhadi
      PubDate: 2014-12-08T02:11:50.026251-05:
      DOI: 10.1111/jai.12636
       
  • The use of trophic resources by Argyrosomus regius (Asso, 1801) escaped
           from Mediterranean offshore fish farms
    • Authors: J. M. Valero‐Rodriguez; K. Toledo‐Guedes, P. Arechavala‐Lopez, D. Izquierdo‐Gomez, P. Sanchez‐Jerez
      Abstract: The population of meagre (Argyrosomus regius) has increased dramatically around the Western Mediterranean, accompanied by a higher seasonal incidence of the species in fishery landings. Presumably because of escapes, this new predator is gaining ground in marine habitats where it was normally not found. Given the lack of knowledge about the potential impact of this locally absent species on ecosystems and fishery resources, the objective of this study was to analyse the diet and predation behaviour of A. regius in order to evaluate its capability to adapt to a new environment as well as to identify its main prey. Stomach contents of 159 individuals were analysed and the identifiable prey items classified into major groups. Results showed that the diet of meagre was remarkably size‐dependent. The commercially important decapod Melicertus kerathurus (Index of Relative Importance IRI: 798.53), and to a lesser extent other crustaceans, were preferred to smaller sizes, while larger individuals gradually shifted to a piscivorous diet, particularly to Platichthys flesus (77.99 IRI). The potential ecological effects on the prey species are discussed, and management measures preventing the establishment of new local populations are suggested in order to harmonize coastal zone management policies with a sustainable production of meagre.
      PubDate: 2014-12-08T02:11:32.893644-05:
      DOI: 10.1111/jai.12649
       
  • Investigation of a subtidal fish community in a south‐western
           Mediterranean settlement area of Morocco
    • Authors: H. Masski
      PubDate: 2014-12-08T01:59:06.42208-05:0
      DOI: 10.1111/jai.12651
       
  • An assessment of bycatch reduction devices in Kuwait's shrimp trawl
           fishery
    • Authors: A. Al‐Baz; W. Chen
      Abstract: Three bycatch reduction devices (BRDs), i.e. the Turtle Excluder Device (TED), Square Mesh Codend (SMC) and Fisheye (FE), were tested to evaluate their feasibility in the Kuwait shrimp‐trawl fishery. All three BRDs could be fitted to a shrimp trawl and normal fishing activities could be conducted both on an industrial trawler and an artisanal dhow boat. The comparisons of the catch from a net equipped with a BRD on one side and a standard net (exact same net configuration but without a BRD device) on the other side of a double‐rigged shrimp trawler (steel boat) showed different results in the three BRD types. The net fitted with a TED performed well without capturing any turtles or large animals, and did not significantly reduce shrimp catch or fish bycatch (124.4: 117.0 and 852.0: 905.8, both P > 0.05). Although the SMC reduced both shrimp catch and bycatch in general, the Wilcoxon's signed rank test showed a significant difference only among bycatch (1034.2: 1147.3, P 
      PubDate: 2014-12-05T02:43:01.544186-05:
      DOI: 10.1111/jai.12653
       
  • Record of lattice blaasop, Takifugu oblongus (Bloch, 1786) from the Sea of
           Oman
    • Authors: L. A. Jawad; D. E. Pitassy
      PubDate: 2014-12-04T05:18:56.440665-05:
      DOI: 10.1111/jai.12640
       
  • Length–weight and length–length relationships and seasonal
           condition factors for two mudskippers, Periophthalmus modestus (Cantor,
           1842) and P. magnuspinnatus (Lee, Choi & Ryu, 1995) (Gobiidae),
           on tidal flats of Korea
    • Authors: G. W. Baeck; J. M. Park
      Abstract: Presented are the length–weight and length–length relationships and condition factors for two mudskippers, Periophthalmus modestus and Periophthalmus magnuspinnatus, on the tidal flats of Korea. Values of the exponent b, estimated by nonlinear least squares from weight and length data, were 3.031 for P. modestus and 3.044 for P. magnuspinnatus. All relationships between total and standard length were linear (r2 > 0.974). The condition factors were significantly higher during the post‐spawning season than at other times for both species.
      PubDate: 2014-12-04T05:17:08.265211-05:
      DOI: 10.1111/jai.12655
       
  • Reference values for selected hematological and serum biochemical
           parameters of Senegalese sole (Solea senegalensis Kaup, 1858) juveniles
           under intensive aquaculture conditions
    • Authors: H. Peres; B. Costas, A. Perez‐Jimenez, I. Guerreiro, A. Oliva‐Teles
      Abstract: This work aims to establish normal reference intervals for selected hemato‐biochemical parameters, based on their potential clinical relevance, and which may contribute to evaluating the health, nutritional and welfare status of Senegalese sole (Solea senegalensis Kaup, 1858) juveniles. Thirty‐one healthy Senegalese sole juveniles grown under intensive aquaculture conditions were used in the study. Based on the robust method with Box–Cox transformation data the established reference intervals for hematological parameters were: hematocrit 12–26%, hemoglobin 2.8–6 g dl−1, erythrocytes 90–97.0% total, leucocytes 4–10% total; erythrocyte indices and differential leucocytes counts were also evaluated. Reference intervals for biochemical parameters were (g dl−1) glucose 19–86 mg dl−1, total protein 2.6–6.3, albumin 1–2.34, globulins 1.8–4.1, lipids 0.7–1.3, triglycerides 0.3–1.8, total cholesterol 0.1–0.9 g dl−1, HDL‐cholesterol 4–65 mg dl−1, LDL‐cholesterol 7–532 mg dl−1, sodium 124–202 mmol L−1), potassium 1.1–4.6 mmol L−1, calcium 7.6–13.2 mg L−1, magnesium 1.8–4.8 mg L−1, inorganic phosphorus 3.4–9.5 mg L−1, alkaline phosphatase 93–598 U L−1, aspartate aminotransferase 118–605 U L−1, lactate dehydrogenase 8.7–782 U L−1, and creatine phosphokinase 31.5–552 U L−1. This data is expected to provide a valuable tool to monitor the stress, health and nutritional conditions of Senegalese sole juveniles under aquaculture production.
      PubDate: 2014-12-04T05:16:49.515991-05:
      DOI: 10.1111/jai.12641
       
  • Effect of photoperiod manipulation on the growth performance of juvenile
           lenok, Brachymystax lenok (Pallas, 1773)
    • Authors: Y. Liu; X. Li, G. F. Xu, S. Y. Bai, Y. Q. Zhang, W. Gu, Z. B. Mou
      Abstract: The effect of four different light regimes on growth was studied in lenok, Brachymystax lenok. Fish with average weights of 5.5 g were subjected to four different photoperiods (0L:24D, 6L:18D, 12L:12D and 24L:0D) for 35 days. The specific growth rate (SGR) of lenok in 24‐h darkness had a significantly higher SGR than those in the continuous light regime (P 
      PubDate: 2014-12-04T05:13:26.670477-05:
      DOI: 10.1111/jai.12632
       
  • Length–weight relationships of four fish species from the
           Curimatidae family, Patos‐Mirim system, southern Brazil
    • Authors: F. Corrêa; E. Fontes De Oliveira, J. Pouey, S. Piedras
      Abstract: Determined were the length–weight relationships (LWRs) of four fish species of the Curimatidae family from the Patos‐Mirim lagoon system. Estimates for three of the species are reported here for the first time.
      PubDate: 2014-12-04T05:12:09.970834-05:
      DOI: 10.1111/jai.12638
       
  • Fish migration through a fish passage associated with water velocities at
           the Changzhou fishway (Pearl River, China)
    • Authors: J. P. Tao; X. C. Tan, Z. Yang, X. Wang, Y. P. Cai, Y. Qiao, J. B. Chang
      Abstract: Hydraulics play an essential role in successful fish passage through fishways, yet little is known about the response of fish species to specific hydraulic characteristics. This study aims to determine the response of fish presence to water velocity that results from the flow regulation in the Changzhou Fishway (CFW). Water velocity meters and fish traps were used in the study to monitor water velocities and the presence of fish species at flood control levels as well as at normal pool levels. Water velocities in the CFW have a varied significantly as result of flow regulation, whereby water velocities at flood control levels are significantly higher than at normal pool levels (P = 0.014). A total of 3558 fish representing 28 species collected in the CFW were divided into two groups by cluster analysis. This type of divergence in species is strongly associated with the two controlled water levels in the fishway, wherein pelagic species predominate at normal pool levels, and demersal species predominate at flood control levels. This study suggests that the variations in water velocities trigger the shifts in species compositions that in the use of CFW.
      PubDate: 2014-12-03T04:13:13.713879-05:
      DOI: 10.1111/jai.12634
       
  • Three major phylogenetic lineages of brown trout (Salmo trutta Linnaeus,
           1758) in the Krka River system (Croatia) revealed by complete
           mitochondrial DNA control region sequencing
    • Authors: M. Jadan; I. Strunjak‐Perović, N. Topić Popović, R. Čož‐Rakovac
      PubDate: 2014-12-02T07:04:42.640662-05:
      DOI: 10.1111/jai.12631
       
  • Implications for catch composition and revenue in changing from diamond to
           square mesh codends in the northeastern Mediterranean
    • Authors: A. R. Eryaşar; H. Özbilgin
      Abstract: The objective of this study was to estimate the potential short‐term economic loss as a result of replacing the commercial diamond codend with a square mesh codend, and to compare fish lengths captured in 40 mm square (S40) vs 44 mm commercial hand‐woven diamond (CD44) mesh codends for red mullet (Mullus barbatus), common pandora (Pagellus erythrinus), bogue (Boops boops), European hake (Merluccius merluccius), axillary seabream (Pagellus acarne), and brushtooth lizardfish (Saurida undosquamis). A total of 20 hauls (10 hauls for S40 and 10 hauls for CD44) were conducted onboard a commercial trawler between 27 February and 11 April 2012 in Mersin Bay in the northeastern Mediterranean. Results showed that the 40 mm square mesh codend caught significantly fewer juveniles of all aforementioned species. However, when changing from the commercial diamond codend to the 40 mm square mesh codend the potential economic loss of revenue was found to be 40% in the study period, which covered the final 6 weeks of the fishing season.
      PubDate: 2014-12-02T07:04:21.71497-05:0
      DOI: 10.1111/jai.12643
       
  • Synchronous patterns of fluctuations in two stocks of anchovy Engraulis
           ringens Jenyns, 1842 in the Humboldt Current System
    • Authors: S. M. Cahuin; L. A. Cubillos, R. Escribano
      Abstract: Most of the studies investigating synchrony in fluctuations of abundance of small pelagic fish have been based on catch data only, which do not describe the dynamics of populations as a relative abundance index. In this paper, catch, biomass, recruitment and recruitment rate, were used to compare synchronous changes for two stocks of anchovy (Engraulis ringens) from 1982 to 2004. One is the North Central Peru stock (NCP) and the other is the shared South Peru‐Northern Chile stock (SPNC). Correlation analysis demonstrated a significant association between population time series, particularly during the growing phase of the stocks. Thus, the synchronous fluctuation pattern of the two stocks is due to the recovery phase and probably driven by density‐independent effects of simultaneous favorable environmental conditions occurring in the two regions. The conclusions were: (i) both NCP and SPNC anchovy stocks are in an overall positive phase of synchrony, (ii) higher correlations in the synchronous pattern of fluctuations occurred during simultaneous increase of biomass, and (iii) short‐term fluctuations were negative when the abundance of the stock was lower and/or impacted by El Niño events.
      PubDate: 2014-12-02T07:03:59.987905-05:
      DOI: 10.1111/jai.12646
       
  • Reproductive ecology and diet of a persistent Ameiurus melas (Rafinesque,
           1820) population in the UK
    • Authors: A. Ruiz‐Navarro; J. R. Britton, M. C. Jackson, G. D. Davies, D. Sheath
      PubDate: 2014-12-02T07:03:37.804685-05:
      DOI: 10.1111/jai.12644
       
  • Length–weight relationships of five fish species from Hormozgan
           coastal waters (northeastern Persian Gulf)
    • Authors: M. Daliri; A. Moradinasab, M. Aghajanpour, M. Andakhsh, H. Raeisi, S. Bagheri Paeinkolaei
      Abstract: The study presents and describes the first length–weight relationships for five fish species: Lagocephalus inermis (Temminck and Schlegel, 1850); Chelonodon patoca (Hamilton, 1822); Ilisha megaloptera (Swainson, 1839); Pseudosynanceia melanostigma Day, 1875; and Chirocentrus nudus Swainson, 1839) from the coastal waters of Hormozgan in the northeastern Persian Gulf.
      PubDate: 2014-12-02T07:03:17.905442-05:
      DOI: 10.1111/jai.12635
       
  • Issue Information
    • PubDate: 2014-11-27T05:59:48.107141-05:
      DOI: 10.1111/jai.12659
       
  • Conference Logos and List of referees
    • PubDate: 2014-11-27T05:59:26.692084-05:
      DOI: 10.1111/jai.12660
       
  • Table of Content
    • PubDate: 2014-11-27T05:59:21.149632-05:
      DOI: 10.1111/jai.12661
       
  • Stock structure analysis of ‘Bombay duck’ (Harpadon nehereus
           Hamilton, 1822) along the Indian coast using truss network morphometrics
    • Authors: D. G. Pazhayamadom; S. K. Chakraborty, A. K. Jaiswar, D. Sudheesan, A. M. Sajina, S. Jahageerdar
      Abstract: Harpadon nehereus, commonly known as ‘Bombay duck’, is a fish with a discontinuous distribution along the Indian peninsula. The fisheries are dominant on the north‐east and north‐west coast but are absent in commercial landings below 15° north latitude. Heretofore stock assessment studies had not considered the various spawning stock components that replenish this fishery, therefore the present study. Fish samples were collected from four locations: two each from the northeast and the northwest coasts. Twenty‐four morphometric variables were measured using a box‐truss network method. Factor analysis of these variables differentiated the east and the west coast fish populations. Multiple comparisons on the factor scores indicated two independent stocks on the east coast, whereas the fishery on the west coast is replenished by a single stock. The important morphometric traits that accounted for most of the stock variations were related to swimming adaptations of the fish. Future stock assessments can consider the population on the west coast as a single stock when formulating management plans. To harvest the resource in a sustainable manner, the maritime states on the west coast should adopt collaborative efforts towards managing this fishery.
      PubDate: 2014-11-10T01:13:01.485984-05:
      DOI: 10.1111/jai.12629
       
  • Short‐term effect of selectivity change in a trawling fishery in the
           Western Mediterranean
    • Authors: M. Samy‐Kamal; A. Forcada, J. L. Sánchez Lizaso
      Abstract: The change of mesh size or shape as a management measure to improve selectivity as proposed by the EU should be assessed using actual fishery data, despite being tested experimentally in previous studies. This work was conducted to evaluate the consequences of inserting either a 40‐mm square‐mesh or a 50‐mm diamond‐mesh (instead of the traditional 40‐mm diamond‐mesh) at codends in commercial Spanish trawlers. Landings in terms of biomass, income and catch composition were compared under commercial conditions. Four métiers were identified in the fishery: European hake (Merluccius merluccius), red mullet (Mullus barbatus), red shrimp (Aristeus antennatus) and Norway lobster (Nephrops norvegicus). No significant differences were observed in biomass or income owing to the new mesh in either European hake or red mullet. In contrast, the total biomass of the red shrimp métier and the biomass of the Norway lobster, Nephrops norvegicus, were significantly higher after the selectivity change. Regarding the catch composition, only the European hake métier showed slight – but not significant – changes after using the new mesh. Considering these results, there was no short‐term effect (substantial biological or economic loss) as previous studies had expected. This could possibly be related to a higher performance of the new gear that may compensate for the lower retention of small sizes.
      PubDate: 2014-11-10T01:12:08.769178-05:
      DOI: 10.1111/jai.12630
       
  • Length–weight relationships of 11 fish species from the Yibin reach
           of the Yangtze River, southwest China
    • Authors: L. Li; Q. W. Wei, J. M. Wu, X. Xie, L. Ren, H. Du
      Abstract: Length‐weight relationships (LWRs) were evaluated for 11 fish species from the Yibin reach of the upper Yangtze River, southwest China. Samples were collected from April 2012 to January 2013. Length‐weight relationships for 11 species were unknown to FishBase, and new maximum lengths are recorded for five species. Results indicate that parameter b ranged from 2.586 (Sinibotia superciliaris) to 3.164 (Rhinogobio ventralis), and r2 values ranged from 0.931 (Sinibotia superciliaris) to 0.996 (Silurus meridionalis).
      PubDate: 2014-11-10T01:11:40.808891-05:
      DOI: 10.1111/jai.12622
       
  • Age and growth of Benthosema pterotum (Alcock, 1890) (Myctophidae) in the
           Oman Sea
    • Authors: S. P. Hosseini‐Shekarabi; T. Valinassab, Z. Bystydzieńska, T. Linkowski
      Abstract: Juvenile and adult specimens of Benthosema pterotum (skinnycheek lanternfish) were collected during several surveys conducted on the Iranian continental shelf of the Oman Sea. Age was estimated by enumeration of growth increments in sagittae otolith sections on the assumption of their daily deposition. Three distinct growth zones in otolith microstructure (central, middle, and external) were defined. These three zones presumably represent increments deposited during successive life history stages, characterized by a different migratory behavior and depth occurrence. The number of increments in the central zone of the B. pterotum otolith (26.8 on average) was thus far one of the lowest in myctophid species studied. A negative correlation between the number of increments in the central and middle zones was observed. This might suggest a functional relation between these two periods of early life history, when fewer larvae in the epipelagic layers may be compensated by a longer non‐migratory behavior of metamorphosis larvae and early juveniles. The maximum number of growth increments in B. pterotum otoliths, i.e. 315, indicated a short lifespan of probably
      PubDate: 2014-10-29T03:04:20.248025-05:
      DOI: 10.1111/jai.12620
       
  • Length‐weight relationships for five nemacheilian loaches
           (Teleostei: Nemacheilidae) from Iran
    • Authors: H. Jamali; R. Patimar, M. Farhadi, A. Doost, V. Daraei
      Abstract: Length‐weight relationships were estimated for five nemacheilian loaches of Iran. Three of these species are endemic to Iran and the L‐W parameters of three species are given for the first time.
      PubDate: 2014-10-28T03:44:53.002352-05:
      DOI: 10.1111/jai.12624
       
  • Length–weight relationships of two endemic fish species in the
           Júcar River Basin, Iberian Peninsula
    • Authors: J. D. Alcaraz‐Hernández; F. Martínez‐Capel, E. J. Olaya‐Marín
      Abstract: This study provides length‐weight relationship (LWRs) information for two fish species (family Cyprinidae) in two headwater streams of the Júcar River Basin (Eastern Iberian Peninsula). Both species are endemic to the Iberian Peninsula and have no previous LWR estimates.
      PubDate: 2014-10-28T03:44:34.884053-05:
      DOI: 10.1111/jai.12625
       
  • Occurrence of Limnoperna fortunei (Dunker, 1857) in the fish diet from a
           south‐eastern Brazilian reservoir
    • Authors: D. M. Rosa; G. B. Santos, P. L. A. Gomes, M. C. S. Campos, J. H. P. Dias
      PubDate: 2014-10-28T02:32:50.561073-05:
      DOI: 10.1111/jai.12623
       
  • Hematological and biochemical responses of juvenile Chinese sturgeon,
           Acipenser sinensis Gray 1835, to exogenous 17β‐estradiol
    • Authors: X. Y. Zhang; H. Du, Y. Z. Zhang, Y. P. Wang, J. J. Cai, Y. Chai, Z. G. Liu, X. M. Qiao, Q. W. Wei
      Pages: n/a - n/a
      Abstract: One of the handicaps to successful large‐scale controlled reproduction of cultured Chinese sturgeon Acipenser sinensis is that broodstocks are generally not well developed due to the lack of certain stimulating factors in the captive environment to trigger the hypothalamus–pituitary–gonad axis. Hormone treatment is one possible means to promote gonad maturation. The study goal was to ascertain the physiological response of the Chinese sturgeon to the exogenous 17β‐estradiol (one of the primary female sex hormones), and estimate its possible effects on gonad development. Serum hormone testosterone (T) and 17β‐estradiol (E2), biochemical and haematological parameters, were tested for 10 weeks (injected with E2 for the first 42 days then cultured for a further 28 days) with 4‐year‐old captive Chinese sturgeon treated in three groups: high dose (HDG, 0.5 mg kg−1, n = 3), low dose (LDG, 0.1 mg kg−1, n = 3), and a control group (injected with 5 ml saline/time/sturgeon, n = 2). Results show that serum E2 concentrations increased during the injection stage of E2 in both HDG and LDG groups, and decreased after injections were terminated; serum testosterone showed the opposite trend, which was mirrored in the serum triglyceride concentrations. The five other serum biochemical parameters (total protein, albumin, globulin, total cholesterol, serum magnesium) ascended during the 70‐day test period, whereas the blood glucose gradually decreased, with the albumin‐to‐globulin ratio falling rapidly after an initial increase soon after injection. The predominant hematological finding was a severe anaemia. Blood parameter changes in the HDG were more significant than in the LDG. Depending on the serum hormone and the increase in the biochemical parameters, a potential estrogenic effect of exogenous E2 on Chinese sturgeon might be produced. However, the decrease in values for the hematological parameters indicated that the health status was somewhat impaired after the injection of E2. From the present findings it is concluded that the physiological responses of Chinese sturgeon to E2 supplementation is predominant, in a dose‐dependent relationship. The results also show that a lower E2 concentration of 0.1 mg kg−1 may be sufficient to constitute the baseline dosage in any further induced maturation studies.
      PubDate: 2014-10-12T02:51:09.136432-05:
      DOI: 10.1111/jai.12610
       
  • Hypoxia tolerance of European sturgeon (Acipenser sturio L., 1758) young
           stages at two temperatures
    • Authors: N. Delage; J. Cachot, E. Rochard, R. Fraty, P. Jatteau
      Pages: n/a - n/a
      Abstract: European sturgeon sensitivity to oxygen depletion at two different temperatures was evaluated with embryos from fertilization to hatching time that were exposed to 90% O2 saturation (% O2 sat), 50% O2 sat and 30% O2 sat at 20 and 26°C; and three‐month‐old juveniles (12 cm length, 7.3 g width) exposed to oxygen challenge from 70% O2 sat to 10% O2 sat at 20 and 25°C. Parameters measured included embryonic survival rate (ESR) and hatch rate (HR); in juveniles the opercular beat frequency (OBF), altered swimming behavior, loss of equilibrium (LOE), and death were recorded. ESR did not differ between oxygen saturation levels for a single temperature but decreased between 20 and 26°C from 60.7 to 21.4% mean survival, respectively. No hatching was observed in embryos exposed to oxygen depletion at 50 and 30% O2 sat, regardless of temperature. The HR was lower at 26°C (15.4% mean) than at 20°C (75.8%) at 90% O2 sat. In embryos, all three oxygen concentrations allowed embryonic survival at the tested temperatures but were insufficient for increased activity such as hatching except at 20°C and 90% O2 sat. In juveniles, OBF peaked at 40% O2 sat at 212 beats per minute at 25°C and at 40–30% O2 sat at 182–183 beats per minute at 20°C. For LOE and death no significant differences were observed with regard to oxygen saturation at 20 and 25°C. Altered swimming behavior appeared at a significantly higher oxygen saturation at 25°C (43.5%) compared to 20°C (34.5%). Anaerobic metabolism was initiated after the OBF peak, which would represent a PO2crit for European sturgeon juveniles under 30 and 40% at 20°C and 25°C, respectively. Temperature increase also adversely affected the threshold of altered swimming behavior, which could be considered as a behavioral indicator of metabolic stress. The probability that the sturgeon embryos are being exposed to harmful temperatures and hypoxic conditions remains a true threat in the Gironde catchment basin.
      PubDate: 2014-10-12T02:50:54.572633-05:
      DOI: 10.1111/jai.12609
       
  • The influence of a longer photoperiod on growth parameters of European sea
           bass Dicentrarchus labrax (Linnaeus, 1758) reared in sea cages
    • Authors: Ş. Yildirim; H. Vardar
      Pages: n/a - n/a
      Abstract: The aim of this study was to investigate the effects of a long‐term photoperiod (15L : 9D) on both the somatic growth and husbandry parameters of sea bass Dicentrarchus labrax. Experiments were conducted in triplicate in high density polyethylene (HDPE) floating cages with net depths of 14 m and diameters of 20 m. Experiments were performed with approximately 170 000 sea bass with initial average weights of 110.63 ± 3.12 g and 110.26 ± 29.70 g for the experimental and control groups, respectively. Beginning in April 2008, extended artificial lighting was used in the experimental cages for 13 months; the control group received no additional illumination. At the end of the experiments, the average weights of the experimental and control groups were 362.13 ± 7.72 and 310.34 ± 18.15 g, respectively. Specific growth rate (SGR) was relatively high in the experimental group compared to the control fish. Feed conversion ratio (FCR) was 2.02 and 2.21 for the experimental and control groups, respectively, with significant differences also found between these groups (P 
      PubDate: 2014-10-10T04:56:47.773351-05:
      DOI: 10.1111/jai.12611
       
  • Latitudinal variation in ontogenetic behaviour of shortnose sturgeon,
           Acipenser brevirostrum Lesueur, 1818: an artificial stream study
    • Authors: E. Parker; B. Kynard
      Pages: n/a - n/a
      Abstract: Two hypotheses were tested on intraspecific variation in early behaviour of Shortnose Sturgeon, Acipenser brevirostrum: (i) ontogenetic behaviour of Shortnose Sturgeon from a northern and a southern population is different, and (ii) dispersal time by southern Shortnose Sturgeon is longer than that of northern Shortnose sturgeon. The hypotheses were tested by observing habitat preference and dispersal of early life stages = ELS (free embryos, larvae, and juveniles) from a northern river (Connecticut River, MA) and from a southern river (Savannah River, SC) in a common garden experiment. Free embryos (yolk‐sac fish) from both rivers were similar, selecting cover and dark habitat, but Savannah River fish used cover less and moved downstream more than Connecticut River fish (a quantitative difference between populations). When fish developed into larvae, fish from both populations preferred an open, bright habitat, left cover, and dispersed downstream mostly at night. Early dispersal of Connecticut River larvae had a 6‐day peak, whereas Savannah River larvae had a weak, 4‐day peak (another quantitative difference between the populations). After the early peak, dispersal by Connecticut River larvae was multi‐peak with low intensity, ending on about day 36 (before larvae developed into juveniles). Savannah River larval dispersal was also multi‐peak, but with a greater intensity, and continued to day 60, when observations ended and fish were juveniles (a qualitative difference between the populations for dispersal cessation). The differences in behaviour between the two populations support both of our hypotheses. The results indicate that behavioural‐genetic differences exist between northern and southern Shortnose Sturgeon populations, particularly for larval dispersal. Conservation strategies, particularly conservation stocking of Shortnose Sturgeon (and other sturgeons), should consider differences between river populations for local behavioural adaptations of ELS.
      PubDate: 2014-10-07T07:01:03.327096-05:
      DOI: 10.1111/jai.12605
       
  • Preliminary genetic variability of Lower Danube River young of the year
           (YOY) beluga sturgeon Huso huso (Linnaeus, 1758) using mtDNA markers
    • Authors: D. Onara; D. Holostenco, M. Paraschiv, R. Suciu
      Pages: n/a - n/a
      PubDate: 2014-10-07T01:05:46.465333-05:
      DOI: 10.1111/jai.12596
       
  • Molecular characterization of the cDNAs of two zona pellucida genes in the
           Chinese sturgeon, Acipenser sinensis Gray, 1835
    • Authors: H.‐M. Yue; H. Cao, X.‐H. Chen, H. Ye, C.‐J. Li, H. Du
      Pages: n/a - n/a
      Abstract: The Chinese sturgeon, Acipenser sinensis, is a large‐sized panadromous cartilagous fish and requires more than ten years to reach sexual maturity. An understanding of the reproductive organs and fertilization process is a precondition for controlled reproduction of this endangered species. The developing oocyte is surrounded by an extracellular matrix composed of the zona pellucide (ZP) protein in several isoforms, all of which play important roles in fertilization and embryo protection. The present study reports the identification of two ZP genes, AsZPAX and AsZPB, in this fish. The full‐length cDNAs of AsZPAX and AsZPB were 2950 base pairs (bp) and 1832 bp, predicting proteins of 946 and 592 amino acid residues, respectively. Both proteins have a conserved ZP domain. In a gene tree, AsZPAX and AsZPB were respectively clustered with their counterparts in other vertebrates. Tissue distribution analysis demonstrated that the AsZPAX RNA was transcribed in both the ovary and the liver, while AsZPB was transcribed exclusively in the ovary. RNA in situ hybridization revealed apparent RNA expression of both AsZPAX and AsZPB in growing oocytes of the 4‐year‐old ovary.
      PubDate: 2014-09-19T02:02:28.604193-05:
      DOI: 10.1111/jai.12586
       
  • Effect of dietary conjugated linoleic acid supplementation on the growth,
           lipid metabolism, and plasma lipid levels of juvenile Amur sturgeon
           (Acipenser schrenckii Brandt, 1869)
    • Authors: C.‐G. Yang; H. Wen, M. Jiang, W. Liu, F. Wu, J. Tian, Q.‐W. Wei
      Pages: n/a - n/a
      Abstract: The study investigated the effects of dietary conjugated linoleic acid (CLA) on the growth, lipid metabolism, and plasma lipid levels of juvenile Amur sturgeon Acipenser schrenckii. In the study design, fish were initially fed a carbohydrate‐enriched diet to obtain ‘high‐lipid or obese’ fish plus a control (NC). In the second step, the high‐lipid fish were divided into four groups and fed increasing levels of CLA at 0% (MC0), 0.5% (MC0.5), 1.0% (MC1.0), and 2.0% (MC2.0) in their diet. The initial control fish (NC) and the other four groups (MC0–2.0) were set up as an experimental series. Each group had three replicate tanks and 15 fish in each tank. After 6 weeks of feeding, specific growth rates and the condition factor were significantly reduced in the 1.0 and 2.0% CLA‐supplemented groups compared with the initial control (NC) and MC0 group. Body lipid content in the 2.0% CLA group was also significantly lower than in the control and other experimental groups. Compared with the MC0 group, lipid liver content in the 2.0% CLA‐supplemented group decreased significantly. Total serum cholesterol was significantly lower in the 1.0% and 2.0% CLA‐supplemented groups. Serum high‐density lipoprotein cholesterol was significantly lower in the 2.0% CLA group than in the MC0 group. There were no differences in survival rate, feed conversion efficiency, body moisture, body protein content, hepatosomatic index, serum triglyceride, or low‐density lipoprotein cholesterol among all experimental groups. The results suggest that adding CLA to fish diets is advisable as it can reduce growth and lipid accumulation in both the body and liver, and affect the regulation of blood lipid levels in juvenile Amur sturgeon.
      PubDate: 2014-09-19T02:01:03.237121-05:
      DOI: 10.1111/jai.12601
       
  • Effects of dietary lipid sources on growth performance, carcass
           composition, and blood parameters of juvenile Chinese sturgeon (Acipenser
           sinensis Gray, 1835)
    • Authors: F. Wu; W. Liu, Q.‐W. Wei, H. Wen, M. Jiang, C.‐G. Yang, J. Tian
      Pages: n/a - n/a
      Abstract: The study investigated the effects of different dietary lipid sources on the growth performance, carcass composition, and blood parameters of juvenile Chinese sturgeon, Acipenser sinensis. Seven iso‐nitrogenous and iso‐energetic diets containing different lipid sources were prepared, i.e. fish oil (FO), soybean oil (SO), groundnut oil (GO), rapeseed oil (RO), corn oil (CO), pork lard (PL), or fish oil: pork lard (1 : 1, FPL). Each experimental diet was fed to triplicate treatments of eight Chinese sturgeon juveniles with initial weights of approximately 47.5 g in indoor tanks for 10 weeks. The FO, SO, and CO treatments had significantly higher weight gain and specific growth rates than the other treatments. Muscle lipid content of the FO treatment was significantly higher than that of the PL treatment, but significantly lower than that of the SO treatment (P 
      PubDate: 2014-09-19T02:00:50.343947-05:
      DOI: 10.1111/jai.12593
       
  • Effects of dietary dextrin on growth, feed utilization and body
           composition of juvenile Chinese sturgeon, Acipenser sinensis Gray, 1835
    • Authors: W. Liu; H. Wen, Q. W. Wei, J. Zhou, M. Jiang, F. Wu, Y. Shi, C. G. Yang, J. Tian
      Pages: n/a - n/a
      PubDate: 2014-09-19T01:58:57.15314-05:0
      DOI: 10.1111/jai.12592
       
  • A short history of sturgeon caviar production in Turkey
    • Authors: Devrim Memis
      Pages: n/a - n/a
      Abstract: Compared to other countries, caviar production in Turkey has a short history, which began principally in the early 1950s, peaked during the 1960s, and began to decline towards the end of the 1970s. Sturgeon fishery was practiced in the estuaries of the rivers Kızılırmak, Yeşilırmak, Sakarya and Çoruh. Thus, processed caviar originated from the districts of Carsamba, Bafra (Samsun City) and Karasu (Sakarya City) and appeared mainly in the markets of Istanbul. Techniques used to capture mature fish were nets set at sea and with hooks (‘karmak’ in Turkish) at the mouth of a river. Two processing techniques were commonly used: (i) malossol/mongol caviar (lightly/highly salted) and (ii) pressed caviar. Landings were mainly recorded in the Istanbul Kumkapı fish hall, reaching 300 tonnes per year in the late 1960s; however, catches declined drastically in the 1970s to only about 30 tonnes. In 1962, caviar production from Acipenser sturio was between 1200 and 1300 kg in the Yeşilırmak River; 1000 to 1200 kg in the Kızılırmak River; and 50 to 80 kg in the Sakarya River. For A. nudiventris, the respective data were 300–400 kg from Yeşilırmak River; 500–600 kg from Kızılırmak River; and 200–250 kg from Sakarya River. The rapid decline in Black Sea sturgeon stocks led to catch restrictions in Turkish coastal areas beginning in 1971. Following the construction of several hydrodams on the main sturgeon rivers in the 1970s, the few sturgeon spawning grounds that remained were drastically affected. Further deterioration of riverine environments was caused by increased pollution in the 1970s–1990s. Sturgeon catches dropped rapidly to less than 10 tonnes after 1975, whereby the fishery collapsed with only a few fish recorded sporadically after 2000. Over the past five years, aquaculture farms began to rear sturgeons for caviar production, with anticipation of initial marketing in 2014–2015. The forecast for 2020 is on the order of 6–8 tonnes of caviar per year.
      PubDate: 2014-09-19T01:56:01.640561-05:
      DOI: 10.1111/jai.12602
       
  • Toxicity of smelter slag‐contaminated sediments from Upper Lake
           Roosevelt and associated metals to early life stage White Sturgeon
           (Acipenser transmontanus Richardson, 1836)
    • Authors: E. E. Little; R. D. Calfee, G. Linder
      Pages: n/a - n/a
      Abstract: The toxicity of five smelter slag‐contaminated sediments from the upper Columbia River and metals associated with those slags (cadmium, copper, zinc) was evaluated in 96‐h exposures of White Sturgeon (Acipenser transmontanus Richardson, 1836) at 8 and 30 days post‐hatch. Leachates prepared from slag‐contaminated sediments were evaluated for toxicity. Leachates yielded a maximum aqueous copper concentration of 11.8 μg L−1 observed in sediment collected at Dead Man's Eddy (DME), the sampling site nearest the smelter. All leachates were nonlethal to sturgeon that were 8 day post‐hatch (dph), but leachates from three of the five sediments were toxic to fish that were 30 dph, suggesting that the latter life stage is highly vulnerable to metals exposure. Fish maintained consistent and prolonged contact with sediments and did not avoid contaminated sediments when provided a choice between contaminated and uncontaminated sediments. White Sturgeon also failed to avoid aqueous copper (1.5–20 μg L−1). In water‐only 96‐h exposures of 35 dph sturgeon with the three metals, similar toxicity was observed during exposure to water spiked with copper alone and in combination with cadmium and zinc. Cadmium ranging from 3.2 to 41 μg L−1 or zinc ranging from 21 to 275 μg L−1 was not lethal, but induced adverse behavioral changes including a loss of equilibrium. These results suggest that metals associated with smelter slags may pose an increased exposure risk to early life stage sturgeon if fish occupy areas contaminated by slags.
      PubDate: 2014-09-04T02:28:46.19732-05:0
      DOI: 10.1111/jai.12565
       
  • Sound production of spawning lake sturgeon (Acipenser fulvescens
           Rafinesque, 1817) in the Lake Winnebago watershed, Wisconsin, USA
    • Authors: C. Bocast; R. M. Bruch, R. P. Koenigs
      Pages: n/a - n/a
      Abstract: The primary goal of this study was to obtain accurate data of previously undocumented lake sturgeon (Acipenser fulvescens Rafinesque, 1817) spawning sounds, generated during wild sturgeon reproduction. Biologists have long known that lake sturgeon produce low‐frequency sounds during spawning bouts; energy from these sounds can break the surface of the water occasionally and propagate harmonics in the terrestrial atmosphere, creating a faint drumming popularly known as ‘sturgeon thunder’. Understanding the contribution of this sonic behavior in context is essential for gaining a more comprehensive scientific appreciation of the process of sturgeon spawning, and accurate acoustic data should prove useful for fisheries managers seeking to monitor or enhance sturgeon stocks for reproductive activity. Recordings were made at several locations on the Wolf and Embarrass rivers during the 2011–2013 spawning seasons. Drumming sounds ranging from 5 to 8 Hz fundamental frequency were evident. Other characteristic noises associated with spawning lake sturgeon, including low‐frequency rumbles and hydrodynamic sounds, were identified. Other high frequency sounds were also discovered. All of these sounds coalesce into a distinctive acoustic signature of lake sturgeon spawning activity. Knowledge of this sonic signature can be used to accurately document reproductive activity at multiple locations over extended periods using remote recording tools and techniques.
      PubDate: 2014-09-04T02:17:35.651628-05:
      DOI: 10.1111/jai.12556
       
  • Seasonal changes in oocyte maturational competence, ovulatory competence
           and gonadotropin sensitivity of ovarian follicles in hybrid sturgeon,
           bester (Huso huso × Acipenser ruthenus)
    • Authors: M. Ishihara; B. Tokui, T. Abe, S. Ijiri, S. Adachi
      Pages: n/a - n/a
      Abstract: Oocyte maturation and ovulation in sturgeon species are induced by injection of hormones such as the luteinizing hormone‐releasing hormone (LHRH). Appropriate timing for the LHRH injection is determined by monitoring the maturational stage of the ovarian follicles. In the present study, ovarian follicles from a group of female bester sturgeon (Huso huso × Acipenser ruthenus) were sampled continuously from September to May and incubated in 100% L‐15 medium (pH 8.2) containing 17α‐hydroxyprogesterone or salmon pituitary extract (SPE) for 48 h at 15°C. After incubation, ratios of oocyte maturational competence (OMC; ability of oocytes to undergo final oocyte maturation in response to maturation‐inducing steroid, MIS), ovulatory competence (OC; ability of ovarian follicles to ovulate under MIS stimulation), and GTH sensitivity (ability of ovarian follicles to respond to GTH) were examined. Almost all oocytes maintained OMC throughout the sampling period. However, OC was acquired in circa December and May. The ratio of follicles that acquired ovulatory competence showed wide variation among individuals. Most females first acquired a higher degree of ovulatory competence in May, although some only did so around December. SPE‐induced oocyte maturation was relatively high throughout the entire experiment, and the ovulation rate showed a tendency similar to that of the ovulatory competence. LHRH‐a injections in May successfully induced ovulation in all females. Higher hatching rates resulted in females whose ovarian follicles showed an increasing trend of ovulatory competence and GTH sensitivity for ovulation in May. These results indicate that ovulatory competence and GTH sensitivity can be used as indicators to determine the timing of LHRH injections for sturgeon.
      PubDate: 2014-09-03T02:43:35.252178-05:
      DOI: 10.1111/jai.12579
       
  • Effects of Ca and Mg concentrations in seawater on the growth and energy
           
    • Authors: M. L. Wang; X. M. Zhang, T. X. Gao, P. D. Zhang
      Abstract: Effects of seawater calcium (Ca) and magnesium (Mg) concentrations on the growth and energy budget of juvenile Paralichthys olivaceus (Temminck & Schlegel, 1846) were investigated at 20°C and a salinity of 30 psu. The Ca/Mg ratio (Ca : Mg = 1 : 3) in the experimental water was kept constant. Five treatments were set: C1, C2, C3, C4, and C5, and the Ca and Mg concentrations were 700, 1100, 1600, 2200, and 2800 (mg L−1), respectively. After a 60‐day feeding trial the P. olivaceus survival rates were not affected significantly by Ca or Mg concentrations in the range of 700–2800 mg L−1. However, the specific growth rates (SGR) and weight gain (WG) of all treatments decreased with ascending Ca and Mg concentrations. The Ca and Mg concentrations had a strong influence on various energy parameters, namely, energy deposited for growth (G), energy lost for respiration (R), and energy lost in excretion (U), but had little influence on energy lost in feces (F). This indicated that the growth rate differences under different concentrations of Ca and Mg mainly resulted from differences of assimilation efficiency and energy channeled into respiration. The highest net growth efficiency was attained at the lowest concentration of Ca and Mg in seawater, and the higher concentrations of Ca and Mg increased the energy channeled to respiration and excretion, which led to significant reduction in growth. Therefore, the optimal growth of P. olivaceus could be obtained by regulating the concentration of Ca and Mg at 700 mg L−1, where the average energy budget was: 100C (100% energy consumed in food) = 47.21 (±0.63) G + 32.89 (±0.42) R + 16.71 (±0.56) F + 3.19 (±0.05) U.
      PubDate: 2014-08-30T03:31:45.303419-05:
      DOI: 10.1111/jai.12477
       
  • Clearhead icefish, (Protosalanx hyalocranius Abbott, 1901) (Salmoniformes,
           Salangidae), a new non‐native species has established a population
           in the Amur River, China
    • Authors: F. J. Tang; W. Liu, J. L. Wang, J. Henne, X. S. Cui
      PubDate: 2014-08-14T06:29:30.065471-05:
      DOI: 10.1111/jai.12454
       
  • Impact of live food on survival and growth of hatchery‐reared sea
           trout (Salmo trutta trutta L.) parr in the wild
    • Authors: R. Czerniawski; J. Domagala, T. Krepski, M. Pilecka‐Rapacz
      Abstract: Survival rates and growth parameters of hatchery‐reared sea trout (Salmo trutta trutta L.) fry were determined after stocking in the wild. The larvae were hatchery‐reared for 12 weeks in two groups: fry were fed either on live zooplankton and live chironomidae larvae (LFG), or fed a pellet diet (PFG). The survival rate and specific growth rates were higher in the LFG than in the PFG group. Most effective for hatchery‐reared fish intended for stocking was the natural, live feed. The mean number of chironomid larvae found in the stomachs of fish that were initially captured in the wild was significantly higher in the LFG than in the PFG group. The live diet supplied in the rearing period had a positive impact on the foraging skills of the sea trout fry and their survival in the wild after their release on 24 April 2010.
      PubDate: 2014-07-29T06:28:41.392399-05:
      DOI: 10.1111/jai.12503
       
  • First length–weight relationships of 11 fish species in the Aegean
           Sea
    • Authors: S. Yapici; P. K. Karachle, H. Filiz
      Abstract: Weight‐length relationships were established for eleven marine fish species caught in the SE Aegean Sea, Turkey. Additionally, a bibliographic review of such relationships for these species was conducted. Based on the results, the values of b parameter varied between 2.477 and 3.496, with one species having isometric growth, five negative and six positive allometric growth. Furthermore, for Aulopus filamentosus there exist no information in the literature, whilst for Callanthias ruber and Gnathophis mystax, there are no such information available from the Mediterranean.
      PubDate: 2014-07-28T06:03:56.7133-05:00
      DOI: 10.1111/jai.12459
       
  • Weight–length and length–length relationships for reef fish
           species from the Cape Verde Archipelago (tropical north‐eastern
           Atlantic)
    • Authors: M. T. Oliveira; M. N. Santos, R. Coelho, V. Monteiro, A. Martins, P. G. Lino
      Abstract: This study reports weight–length and length–length relationships for selected coastal reef fish species of the Cape Verde Archipelago (tropical north‐eastern Atlantic). Specimens were caught with different types of gear (long‐lines, hand‐lines, purse‐seines and traps) during commercial fishing activities and sampled during fish market operations. A total of 8328 individuals were sampled, representing 29 species from 14 Families. This study provides the first references on weight–length and length–length relationships for five and 23 fish species worldwide, for 10 and 24 species for the Eastern Atlantic and for 12 and 26 species for Cape Verde Archipelago, respectively. Additionally, it provides revised weight–length relationships for 11 species from Cape Verde waters.
      PubDate: 2014-07-10T02:49:11.807088-05:
      DOI: 10.1111/jai.12497
       
  • Spatiotemporal occurrence and feeding habits of tonguefish, Cynoglossus
           lighti Norman, 1925, larvae in Ariake Bay, Japan
    • Authors: G. Kume; K. Furumitsu, H. Nakata, T. Suzuki, M. Handa, A. Yamaguchi
      Abstract: Spatiotemporal occurrence and feeding habits of tonguefish (Cynoglossus lighti Norman, 1925) larvae were investigated in an offshore area (>5 m in depth) of the inner part of Ariake Bay, Japan. All specimens were symmetric, free‐swimming larvae. Although their seasonal abundance and distribution in the study site varied from year to year, spawning started in June and the larval abundance was high in August and September with a wide distribution in the inner part of the bay. Both present and previous study results strongly suggest that larvae may settle primarily in the estuary and near‐shore areas of Ariake Bay after their wide distribution in the offshore area of the bay during the free‐swimming stage. Larvae showed a clear feeding rhythm in which they fed on prey mainly during the daytime. Larvae fed exclusively on copepods, and identified prey were mostly Paracalanidae (mainly Parvocalanus crassirostris), Microsetella norvegica, and Oithona davisae. Pre‐metamorphosis larvae fed primarily on Paracalanidae and O. davisae, whereas O. davisae formed a smaller proportion of the early‐metamorphosis diet. In early metamorphoses, larvae fed preferentially on Paracalanidae and M. norvegica.
      PubDate: 2014-07-10T02:45:21.155113-05:
      DOI: 10.1111/jai.12498
       
  • Length–weight relationships for freshwater fish species from the
           Pantanal of the Negro River, Brazil
    • Authors: V. F. Batista‐Silva; D. Bailly, É. A. Gubiani, F. E. S. Costa, V. L. Lescano de Ameida, T. Liparelli
      Abstract: The present study describes the length‐weight relationships (LWRs) of 28 species captured in Santa Virgínia Bay, in the Pantanal of the Negro River, Mato Grosso do Sul State, Brazil, over 3 years (1999 to 2001). The study provides the first references on LWRs for thirteen of these species.
      PubDate: 2014-07-07T04:16:28.621174-05:
      DOI: 10.1111/jai.12495
       
  • Morphological parameters of abundant and threatened chondrichthyans of the
           northwestern Mediterranean Sea
    • Authors: C. Barría; J. Navarro, M. Coll, U. Fernandez‐Arcaya, R. Sáez‐Liante
      Abstract: The diversity of chondrichthyans in the Mediterranean Sea is relatively high; however, available data indicate that this group is declining in abundance and several species are becoming rare. As a result, the collection of biological data is a priority for demographic models, stock assessments, and food web analysis. In the present study, we report morphological parameters and length–weight relationships of several chondrichthyan species, both abundant and threatened, from the western Mediterranean Sea. Samples were obtained with commercial and scientific bottom trawl vessels between 2001 and 2013. A total of 893 individuals belonging to 11 families and 20 species were weighed and total lengths measured. In addition, seven species of large demersal sharks were measured and length–length relationships obtained to study the relationships between different body length measurements. All species showed positive allometric or isometric growth, except for Centroscymnus coelolepis. The results of the length–weight relationships reveal differences between the western Mediterranean and nearby areas, depending on the species studied.
      PubDate: 2014-07-07T03:06:21.044171-05:
      DOI: 10.1111/jai.12499
       
  • Growth pattern of an endemic and endangered West Balkan Peninsula trout
           species (Salmo lourosensis, Delling, 2010)
    • Authors: A. Ntakis; R. Liasko, A. Oikonomou, I. D. Leonardos
      PubDate: 2014-07-07T02:48:43.987022-05:
      DOI: 10.1111/jai.12493
       
  • Length–weight relationships of fish species associated with the
           mangrove forest in the southwestern Terminos Lagoon, Campeche (Mexico)
    • Authors: L. E. Amador‐del Ángel; E. Guevara‐Carrió, R. Brito, A. T. Wakida‐Kusunoki
      Abstract: Length–weight relationships (LWR) were calculated for 18 species representing 11 families of fishes. A total of 958 fish specimens from the southwestern Terminos Lagoon, Campeche (Mexico), several of which had none or few LWRs available in FishBase, were sampled (except December) using a shrimp otter trawl net from September 2003 to August 2004. Sample sizes ranged from seven Mugil curema and Archosargus probatocephalus individuals to 250 Eugerres plumieri.
      PubDate: 2014-07-07T02:27:14.845268-05:
      DOI: 10.1111/jai.12490
       
  • Presence of prohibited fishes in the Brazilian aquarium trade:
           effectiveness of laws, management options and future prospects
    • Authors: A. L. B. Magalhães
      PubDate: 2014-07-07T02:08:38.028365-05:
      DOI: 10.1111/jai.12491
       
  • Evaluation of Lactobacillus paracasei subsp. tolerans isolated from
           Jenyn's sprat (Ramnogaster arcuata) as probiotic for juvenile rainbow
           trout Oncorhynchus mykiss (Walbaum, 1792)
    • Authors: A. Lopez Cazorla; M. G. Sica, L. I. Brugnoni, P. L. Marucci, M. A. Cubitto
      Abstract: A lactic acid bacterial strain, Lactobacillus paracasei subsp. tolerans F2, isolated from the intestine of Ramnogaster arcuata, was evaluated as a growth promoter in juvenile rainbow trout Oncorhynchus mykiss (Walbaum, 1972) farming. In addition, the safety of the strain was assessed according to the FAO recommendations. Strain F2 was susceptible to most antibiotics tested and no evidence of hemolytic activity was found. When the strain of Lactobacillus paracasei subsp. tolerans F2 was administered with food, no adverse effects on health were observed and fish biomass increased 12% more in the treatment group than in the control group. Significant differences were detected in the specific growth rate and feed conversion ratio. In the group receiving Lactobacillus paracasei subsp. tolerans F2‐supplemented feed, quantitative differences in the microbial composition of fish feces with respect to the control group were observed. An important decrease in fungi and enterobacteria was observed in feces from the treatment group, coincident with an increase in lactic acid bacteria. This result would indicate a change in the composition of the intestinal microbiota of fish treated with the putative probiotic. These results suggest that the strain of Lactobacillus paracasei subsp. tolerans F2 has the application potential to improve the performance in rainbow trout farming.
      PubDate: 2014-07-07T02:08:35.67106-05:0
      DOI: 10.1111/jai.12496
       
  • Diet composition, feed preferences and mouth morphology of early stage
           silver therapon (Leiopotherapon plumbeus, Kner 1864) larvae reared in
           outdoor tanks
    • Authors: F. A. Aya; M. N. C. Corpuz, L. M. B. Garcia
      Abstract: This study examined the diet composition, feeding preferences, and mouth morphology of the silver therapon (Leiopotherapon plumbeus, Kner 1864) larvae under captive conditions. Larvae were reared in outdoor tanks (4 m3) with natural food grown 2 weeks prior to start of larval rearing. Food preference was measured by the Chesson's electivity index (αi). Gut content analysis of larvae sampled between 5 and 25 days after hatching (DAH) showed the dominance in the diet by zooplankton, mainly copepod nauplii, cladocerans and insect larvae. Small fish larvae (5–9 DAH; 3.32–6.29 mm standard length) preferred cladocerans, ciliates and copepod nauplii; whereas older larvae (12–25 DAH; 5.45–19.26 mm standard length) preferred insect larvae over cladocerans and adult insects. The mouth gape size at 5 DAH was 359 μm and increased to 3.75 mm at 40 DAH when body size grew at an average rate of 0.59 mm d−1. The standard length (SL) of L. plumbeus larvae was strongly associated with mouth size (r2 = 0.98, P 
      PubDate: 2014-07-07T02:08:32.825234-05:
      DOI: 10.1111/jai.12486
       
  • Immune responses and intestinal morphology of striped catfish,
           Pangasianodon hypophthalmus (Sauvage, 1878), fed dietary nucleotides
    • Authors: M. Yaghobi; S. Dorafshan, M. Akhlaghi, F. Paykan Heyrati, N. Mahmoudi
      Abstract: The present study was conducted to evaluate the effects of dietary nucleotides (NT) on growth performance, immune responses, and intestinal morphology of striped catfish, Pangasianodon hypophthalmus. Different levels of NT (0, 0.25. 0.5, 0.75, and 1% weight per weight, WW−1) were used in the basal diet and then randomly allocated to triplicate groups of fish with an average initial weight of 1.52 ± 0.11 g for 10 weeks. Nucleotide supplementation did not improve growth parameters significantly (P > 0.05). Feeding fish with a NT‐containing diet significantly improved ACH50 activity and IgM levels in comparison to the control group (P 
      PubDate: 2014-07-02T01:13:02.406764-05:
      DOI: 10.1111/jai.12489
       
  • Length–weight relationships of seven freshwater fishes from the
           JiangSu province, China
    • Authors: S. K. Tang; T. Q. Zhang, M. H. Wang, G. Zhou, L. Q. Zhong, D. M. Li, J. L. Pan
      Abstract: The length‐weight relationships (LWRs) are presented for seven freshwater fish species (Odontobutis potamophila, Protosalanx chinensis, Acheilognathus chankaensis, Megalobrama skolkovii, Pelteobagrus vachelli, Macropodus chinensis, Pseudobrama simoni) from JiangSu province in China. A total of 1340 specimens were sampled and measured between August 2012 and September 2013. No information regarding the LWRs of these species was available in FishBase.
      PubDate: 2014-06-30T07:28:30.821352-05:
      DOI: 10.1111/jai.12492
       
  • Length‐weight relationships of 26 fish species from the streams of
           the upper section of the Paraguay River basin (Mato Grosso, Brazil)
    • Authors: V. A. Oliveira; S. M. Loverde‐Oliveira, L. A. Mateus, F. Teixeira‐de Mello
      Abstract: This study provides data on the length‐weight relationships (LWR) for 26 tropical fish species collected in August 2010 (dry season) and May 2011 (wet season), and represents the first LWR references for these species in the small tributary streams flowing into the major rivers of the Pantanal Matogrossense, Brazil.
      PubDate: 2014-06-30T07:28:28.567125-05:
      DOI: 10.1111/jai.12487
       
  • Length–weight relationships for 15 fish species from the Hunan
           Hupingshan National Nature Reserve in central China
    • Authors: J. Y. Xie; Z. J. Kang, J. Yang, D. D. Yang
      Abstract: Length–weight relationships (LWRs) were estimated for 15 fish species representating 15 genera and six families from the Hunan Hupingshan National Nature Reserve, China. Six species are endemic to China, one of which is also endemic to the Yangtze River. The b values of all species were within the expected ranges, varying between 2.68 and 3.26. Data of 11 species represent the first description of LWRs and nine species have new records of maximum length.
      PubDate: 2014-06-30T07:18:14.338833-05:
      DOI: 10.1111/jai.12465
       
  • Evaluating the genetic status of the IUCN vulnerable endemic Macedonian
           shad (Alosa macedonica, Vinciguerra, 1921) from Lake Volvi
    • Authors: I. A. Giantsis; S. Kechagia, A. P. Apostolidis
      PubDate: 2014-06-30T07:03:26.942374-05:
      DOI: 10.1111/jai.12494
       
  • Length–weight relationships for four small fish species caught in
           wetlands of central Yangtze River, China
    • Authors: W. Xiong; J. Tao, D. C. Zhang, C. L. Liu, D. K. He, Y. F. Chen
      Abstract: Length–weight relationships for four native species (Oryzias latipes Temminck & Schlegel, 1846; Rhodeus ocellatus Kner, 1866; Rhinogobius giurinus Rutter, 1897; and Micropercops swinhonis Günther, 1873) were determined. The fish were collected from the wetlands of the central Yangtze River, in Wuhan, Hubei Province, China. Samples were obtained from May 2012 to January 2013. Length–weight relationships for O. latipes were determined for the first time.
      PubDate: 2014-06-23T08:31:32.028436-05:
      DOI: 10.1111/jai.12484
       
  • Comparative analysis of intermuscular bones in three strains of common
           carp
    • Authors: D.‐C. Cao; Y.‐Y. Kuang, X.‐H. Zheng, G.‐X. Tong, C.‐T. Li, X.‐W. Sun
      Abstract: The objective was to document the variations in the intermuscular bone counts among three carp strains: mirror carp, hybrid carp [Boshi carp (Cyprinus pellegrini) × Heilongjiang carp (Cyprinus carpio)], and a cold‐resistant strain of Hebao carp. The intermuscular bone counts, lengths, and weights were obtained from 146 fish; the bone count ranged from 55 to 110 (mean 92.85) among the three strains. Mirror carp had the lowest number of intermuscular bones and a higher coefficient of variation in counts relative to the other two species. There was no relationship between the intermuscular bone counts to standard length or body length. Similarly, there was no difference in the intermuscular bone count or shape between the left and right sides of the body. However, the count was significantly higher (P 
      PubDate: 2014-06-23T08:30:39.174171-05:
      DOI: 10.1111/jai.12483
       
  • Length‐weight relationships of 11 fish species from the upper Jinsha
           River, China
    • Authors: P.‐C. Lin; Z.‐G. Miao, X. Gao, H.‐Z. Liu
      Abstract: Length‐weight relationships (LWR) are described for eleven indigenous fishes from the upper Jinsha River, which is the upper stretch of the Yangtze River, China. This is the first record of length‐weight relationships for ten of these species in FishBase and new maximum lengths are recorded for seven species.
      PubDate: 2014-06-20T06:25:48.268424-05:
      DOI: 10.1111/jai.12466
       
  • Conclusions and recommendations of the 7th International Symposium on
           Sturgeons: Sturgeons, Science and Society at the cross‐roads –
           Meeting the Challenges of the 21st Century
    • Authors: H. Rosenthal; J. Gessner, P. Bronzi
      First page: 1105
      PubDate: 2014-11-10T01:09:47.552685-05:
      DOI: 10.1111/jai.12614
       
  • Migration of juvenile and sub‐adult Chinese sturgeon Acipenser
           sinensis Gray, 1835 in the Yangtze River, China below the Gezhouba Dam
    • Authors: C. Y. Wang; H. Du, H. Zhang, J. M. Wu, Z. G. Liu, Q. W. Wei
      First page: 1109
      Abstract: Acoustic telemetry data and recapture information were collected to study the distribution and migration of sub‐adult and juvenile Chinese sturgeon Acipenser sinensis. From 2007 to 2012, 187 537 tagged cultured fish (4637 sub‐adults and 182 900 juveniles) were released at two sites on the Yangtze River. Subsequently, 482 fish were caught, comprising 198 cultured fish and 284 wild fish, mostly near sandbanks and sandbars with flat topography and slow water flow rates. Acoustic monitoring showed that a single sub‐adult fish migrated upstream to the spawning grounds just below the Gezhouba Dam, a distance of 157 km at an upstream ground speed of 0.40–1.40 km h−1 (mean, 0.70 km h−1). Nine acoustically monitored sub‐adults made a downstream migration of 45–1521 km at a ground speed of 0.08–3.80 km h−1. The ground migration speed of fish upstream to Wuhan (rkm 1678–1071) was significantly lower than that from Wuhan to the Yangtze estuary (rkm 1071–94). There was no significant difference in the ground migration speed between cultured and wild individuals. Knowledge of the movement and migration patterns of the stocked juvenile and sub‐adult Chinese sturgeon will help to locate areas of the downstream channel in the lower reaches of the Yangtze River critical to the sturgeon and to evaluate the potential impact of the Three Gorges Dam on their downstream migration.
      PubDate: 2014-09-24T04:29:54.308744-05:
      DOI: 10.1111/jai.12599
       
  • Spawning migrations and reproductive parameters of the kaluga sturgeon,
           Huso dauricus (Georgi, 1775), and Amur sturgeon, Acipenser schrenckii
           (Brandt, 1869)
    • Authors: V. N. Koshelev; G. Ruban, A. Shmigirilov
      First page: 1125
      Abstract: Mature specimens of kaluga sturgeon Huso dauricus (Georgi, 1775) and Amur sturgeon Acipenser schrenckii (Brandt, 1869) were previously abundant in catches throughout their range that included the Amur River basin and coastal waters of the Sea of Okhotsk and Sea of Japan. However, both kaluga and Amur sturgeon now reach maturity mainly in the Amur Estuary and sea waters. The most intensive migration from the estuary to the river takes place in spring, from mid‐May to mid‐June (with a peak 21–25 May), and in autumn, from mid‐August to late September (with a peak 16–25 August). The migration of kaluga and Amur sturgeon spawners is anadromous. Spring spawners numerically prevail over autumn spawners in the kaluga sturgeon, whereas an inverse situation is observed in the Amur sturgeon. Average body sizes of females in both species and that of male kaluga sturgeon have decreased over the past 5–10 years. The Amur and kaluga sturgeons from the Amur River mature earlier than those from the Amur Estuary. The average absolute fecundity of both species has decreased in recent years because of a reduction in the proportion of spawners in older age classes.
      PubDate: 2014-08-18T07:55:46.598336-05:
      DOI: 10.1111/jai.12549
       
  • Seasonal diet composition of juvenile and adult pallid sturgeon,
           Scaphirhynchus albus (Forbes & Richardson, 1905), in the channelized
           lower Missouri River
    • Authors: K. R. Winders; J. E. Dattilo, T. R. Huffmon, V. H. Travnichek
      First page: 1133
      Abstract: Although habitat alterations and reproductive success are the main contributors to declines of the pallid sturgeon, Scaphirhynchus albus (Forbes & Richardson, 1905) listed in 1990 as federally endangered, disrupted trophic links within diets of pallid sturgeon populations have been hypothesized as partial contributors. The objective of this study was to evaluate pallid sturgeon food habits within a 500 km reach of the lower channelized Missouri River using non‐lethal pulsed gastric lavage. Trotlines, gill nets, trammel nets, and benthic otter trawls were used to collect 284 pallid sturgeon, which ranged in fork length from 265 to 1047 mm. Stomach contents of pallid sturgeon included fish (Cyprinidae and Ictaluridae), aquatic insects, copepods, leeches, and mussels. Cyprinids were the most abundant prey item; ictalurids were also of high abundance. Otter trawl catch rates of ictalurids and cyprinids were not spatially correlated to the respective abundances in pallid sturgeon diets; however, the ratio of the average catch rate to the average number of fish per pallid sturgeon indicated preference for cyprinids (1.5 : 1), particularly Macrhybopsis species, relative to ictalurids (7 : 1). Our results support the need for management of native cyprinids, especially Macrhybopsis species, which have been in decline within the entire range of the pallid sturgeon. However, pallid sturgeon are also able to consume ictalurids, a species which has remained in high abundance in the lower Missouri River.
      PubDate: 2014-07-29T06:28:36.845458-05:
      DOI: 10.1111/jai.12540
       
  • Linking movements of lake sturgeon (Acipenser fulvescens Rafinesque, 1817)
           in a small hydroelectric reservoir to abiotic variables
    • Authors: C. A. McDougall; P. J. Blanchfield, W. G. Anderson
      First page: 1149
      Abstract: Quantifying the extent to which abiotic factors influence lake sturgeon (Acipenser fulvescens Rafinesque, 1817) movement and utilization of areas where they are susceptible to entrainment may be useful for management of hydroelectric operations. Over two open–water seasons, acoustic telemetry was used to monitor tagged adults (n = 25) and subadults (n = 24) throughout a 9.8 km long run‐of‐the‐river reservoir located on the Winnipeg River, Manitoba, Canada. Movement and utilization patterns were examined for correlation with abiotic variables. Despite considerable individuality, the adult sample population increasingly utilized the lower sections of the reservoir when air and water temperatures were high, daylight hours were long, river flow was increasing, and flows were high. However, our hypothesis of a pronounced concentration of Lake Sturgeon occurring immediately upstream of the generating station when high flows coincided with the summer/fall period was not supported. This may be attributed to the presence of a shallow river narrows located 2.1 km upstream of the station, which appeared to restrict the extent of seasonal/flow influenced downstream movement by adults. Movements of individual subadults were also correlated to seasonal and flow variables, but directionality was not consistent and population level trends in utilization did not appear to be correlated to abiotic variables. Results suggest that in small reservoirs, adult utilization of the areas immediately upstream of hydroelectric facilities may be influenced more by seasonality than by flow conditions.
      PubDate: 2014-08-13T07:38:44.391619-05:
      DOI: 10.1111/jai.12546
       
  • Effect of velocity regime on ontogenetic dispersal and habitat use of
           Kootenai River White Sturgeon (Acipenser transmontanus, Richardson, 1836)
           early life stages: An artificial stream study
    • Authors: B. Kynard; E. Parker, B.E. Kynard, M. Horgan
      First page: 1160
      Abstract: The effect was studied of two channel velocity regimes (slow regime = mean, 16.9 cm s−1; fast regime = mean, 23.4 cm s−1) on the behaviour and dispersal of Kootenai River white sturgeon Acipenser transmontanus early life stages (ELS = free embryos, larvae, early‐juveniles) in artificial streams. A conceptual model incorporating velocity effects on ELS behaviour and dispersal follows that: (1) most free embryos hide under cover and do not disperse in any velocity; (2) the velocity regime has the greatest effect on peak dispersal by larvae − dispersal is intense and short (11 and 13 days in 16.9 and 23.4 cm s−1, respectively); and (3) the long peak and valley dispersal (alternating periods of intense and slow dispersal) by post‐peak larvae and early‐juveniles, which lasts to day 74 post‐hatch (early‐September) for some fish, is not affected by the velocity regime. Edge velocity habitat (about 4 cm s−1 between eddy and channel velocities) was used by 65% of the late‐larvae foraging on drift during the day in either a slow or fast velocity regime, the edge being used even more at night (75% in fast velocity, 82% in slow velocity). Early‐juveniles also used edge habitat. Regulation of river flow should maintain a minimum 23 cm s−1 bottom velocity regime in the larval dispersal reach to trigger an intense dispersal from the spawning reach and enable fish to disperse quickly downstream.
      PubDate: 2014-10-03T06:09:37.361708-05:
      DOI: 10.1111/jai.12595
       
  • Morphometric comparisons of the Gulf sturgeon (Acipenser oxyrinchus
           desotoi Mitchill, 1815) in western and eastern population extremes
    • Authors: P. F. Mickle; M. S. Peterson, J.‐M. Havrylkoff, P. O. Grammer
      First page: 1168
      Abstract: The Gulf sturgeon, Acipenser oxyrinchus desotoi Mitchill 1815, is an anadromous fish native to the Gulf of Mexico (GOM). This threatened species ascend northern GOM rivers ranging from the Pearl River, Louisiana to the Suwannee River, Florida. The drainage fidelity seen within this species coupled with the complex migration patterns create many unknowns concerning the functionality between drainages and size classes. Being a threatened species that cannot be sacrificed, morphometric measurements are difficult to acquire due to minimized handling times and non‐lethal data collection methods. Seven morphometric measurements of Gulf sturgeon were compared between western and eastern GOM rivers and multiple size classes (juvenile, sub‐adult, and adult). Principal Component, Discriminant Function, and Maximum Chance Criterion analyses were conducted and identified differentiating morphometrics and classified groupings among size classes and rivers of Gulf sturgeon. This morphometric approach has the potential to be used in parallel with molecular findings and should allow managers to identify sub‐populations for a variety of threatened and endangered species.
      PubDate: 2014-08-22T05:27:06.712903-05:
      DOI: 10.1111/jai.12559
       
  • Analysis of δ13C in lake sturgeon (Acipenser fulvescens [Rafinesque
           1817]) fin and muscle tissue: an application of three arithmetic lipid
           correction models
    • Authors: D. Braun; I. D. Phillips, B. Wissel
      First page: 1174
      Abstract: For stable isotope diet studies, fin tissue is preferred over muscle tissue because it is less intrusive and avoids unnecessary stress or mortality, particularly in endangered species, such as lake sturgeon (Acipenser fulvescens). Yet to ensure accurate analysis of lake sturgeon feeding habits the development of a muscle‐fin tissue fractionation factor is essential to remove lipid bias within different tissue types. We corrected for lipids in muscle and fin tissue by using three mathematical correction methods on 87 lake sturgeon from the Saskatchewan River in Saskatchewan, Canada from May to October 2011 (weight range: 0.60–43.30 kg; fork length range: 0.42–1.62 m). The mean respective fractionation factor for McConnaughey and McRoy (Mar. Biol., 53, 1979, 257) and Fry et al. (Estuaries, 26, 2003, 82) models were not significantly different from each other (P > 0.05, 0.86 and 0.80‰), and neither significantly differed from a 1 : 1 line (slope = 0.97, r2 = 0.80 and 0.81, respectively). Conversely, the Post et al. (Oceologia, 152, 2007, 179) model results were significantly different from the 1 : 1 line with a low r2 of 0.19 and a fractionation factor significantly different from the other two models (P 
      PubDate: 2014-11-27T05:59:38.662356-05:
      DOI: 10.1111/jai.12627
       
  • Selective utilization of fatty acids by Chinese sturgeon (Acipenser
           sinensis Gray, 1835) during gonadal development and first year juvenile
           growth
    • Authors: J.‐J. Liu; Q.‐F. Li, B.‐F. Guo, Y. Gao
      First page: 1181
      Abstract: The aim of this study was to investigate the utilization of essential fatty acids by Chinese sturgeon Acipenser sinensis during gonadal development and juvenile growth stages. Muscles and eggs from stages II to V control‐bred broodfish were sampled to analyze whether fatty acids were transferred from the muscle to the gonads. Fatty acids in the muscles of broodstock females were relatively stable from stages II to IV, whereas the total PUFA content, as well as the ratio of n‐3/n‐6 PUFA and DHA/EPA in stage V gonads were significantly higher than in the corresponding muscle tissue. Naturally spawned eggs collected from the Yangtze spawning area were hatched and cultured in the same environment and with the same feeding strategy as the closed‐cycle controll‐bred eggs and juveniles. However, the relative content of C18:1n‐9 and C22:6n‐3 in the naturally spawned eggs was significantly higher. Naturally spawned juvenile n‐3 PUFA was also significantly higher than in control‐bred juveniles. These findings illustrated that PUFA, especially the DHA, EPA and ARA, are of great absorption and utilization in gonadal development and juvenile growth of Chinese sturgeon.
      PubDate: 2014-10-29T03:01:06.873868-05:
      DOI: 10.1111/jai.12612
       
  • Proximate composition and fatty acid profile in different tissues of wild
           female Chinese sturgeon (Acipenser sinensis Gray, 1835)
    • Authors: C. Song; P. Zhuang, L. Z. Zhang, T. Zhang, J. Y. Liu
      First page: 1203
      PubDate: 2014-08-30T03:33:22.658434-05:
      DOI: 10.1111/jai.12583
       
  • Discriminant analysis of blood biochemical parameters at different
           developmental gonad stages and gender identification for controlled
           breeding of Amur sturgeon (Acipenser schrenckii, Brandt, 1869)
    • Authors: L. Z. Zhang; T. Zhang, P. Zhuang, F. Zhao, B. Wang, G. P. Feng, C. Song, Y. Wang, S. J. Xu
      First page: 1207
      Abstract: Male and female Amur sturgeon (Acipenser schrenckii) at sexual maturity (age 7 years) were identified under controlled breeding conditions, and the plasma biochemical parameters were determined at different developmental stages of the gonads. The results showed that there was significant difference of the plasma calcium (Ca2+) and lactate dehydrogenase (LDH) content between the sexually mature males and females. The LDH content in males was highest, while the Ca2+ concentration was lowest. During different gonad developmental stages (II,III,IV‐A and IV‐B) of the, the content in the ovaries of plasma total protein (TP), globulin (GLB), total bilirubin (TBIL), triglycerides (TRIG), Ca2+ and inorganic phosphorus (P−) initially showed an upward trend, and decreased thereafter. The values of albumin (ALB), albumin/globulin (A/G) and total cholesterol (CHOL) increased gradually from stage of II to IV‐B, and showed significantly higher levels at the stage of IV‐A to IV‐B (P 
      PubDate: 2014-09-11T00:31:21.67945-05:0
      DOI: 10.1111/jai.12584
       
  • Morphological and osteological development during early ontogeny of
           Chinese sturgeon (Acipenser sinensis Gray, 1835)
    • Authors: J. Ma; P. Zhuang, B. Kynard, T. Zhang, L. Z. Zhang
      First page: 1212
      PubDate: 2014-09-11T00:34:25.92974-05:0
      DOI: 10.1111/jai.12585
       
  • Expression pattern of somatolactin in the Chinese sturgeon, Acipenser
           sinensis Gray, 1835
    • Authors: X.‐Q. Leng; C.‐J. Li, H. Cao
      First page: 1222
      Abstract: Somatolactin (SL) is a pituitary hormone specific to fish and is reported in a variety of teleost species. Although it appears to be involved in many different physiological processes, its biological functions are poorly understood in Acipenseriformes. In this paper the expression pattern of this protein is characterized in Chinese sturgeon (Acipenser sinensis). Structure analysis showed that AsSL had a 24aa signal peptide and a 208aa mature protein, one N‐glycosylation site at positions 145‐147 and seven Cys residues conserved with other SLs. The antiserum was raised against a 15 aa antigen, derived from the Chinese sturgeon somatolactin (AsSL) amino acid sequence. Western blot analysis showed the pituitary‐specific expression of AsSL. In situ hybridization revealed that the mRNA of AsSL was expressed mainly in pars intermedia (PI), although also slightly in proximal pars distalis (PPD), cells expressing AsSL disperse throughout the pars intermedia. These findings provide useful information for future physiological research in Chinese sturgeon.
      PubDate: 2014-09-11T00:59:13.209264-05:
      DOI: 10.1111/jai.12587
       
  • Salinity effects on Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus
           Mitchill, 1815) growth and osmoregulation
    • Authors: P. J. Allen; Z. A. Mitchell, R. J. DeVries, D. L. Aboagye, M. A. Ciaramella, S. W. Ramee, H. A. Stewart, R. B. Shartau
      First page: 1229
      Abstract: The Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus Mitchill, 1815) is an anadromous sturgeon species, yet little is known with regard to its osmoregulatory ability and habitat use at early life stages. In order to examine whether salinity poses a physiological challenge to juvenile Atlantic sturgeon near the sizes where they may begin to move into saline habitats, growth and osmoregulatory ability were tested. Juvenile Atlantic sturgeon (mean initial weight: 440 g) were acclimated to one of three salinity conditions (0, 10, or 33 ppt) representing the range of salinities they would be expected to encounter. Growth was measured over a 6‐month period, and osmoregulatory ability (i.e. blood plasma osmolality and ionic concentrations) was measured after 4 months. Mean weight and length increased in all treatments, but fish in 0 and 10 ppt grew more than fish in 33 ppt. Blood plasma osmolality was regulated at similar levels regardless of salinity. Therefore, juvenile Atlantic sturgeon have the physiological capability to move between salinity habitats, but grow faster in low salinities.
      PubDate: 2014-07-29T06:28:49.557538-05:
      DOI: 10.1111/jai.12542
       
  • Biochemical comparison between eggs from female Chinese sturgeon
           (Acipenser sinensis Gray, 1835) reconditioned in freshwater and eggs from
           wild females: evaluation of female reconditioning as a conservation
           culture technique
    • Authors: W. Li; Q.W. wei, L. Shen
      First page: 1237
      Abstract: Chinese sturgeon (Acipenser sinensis Gray, 1835) eggs from wild females (‘wild eggs’) and eggs from females reconditioned in freshwater (‘freshwater eggs’) were compared for biochemical factors related to their good chemical and physical condition and successful fertilization. Dry weights did not differ between the two groups of eggs. Wild eggs had a significantly higher protein content but lower lipid content than freshwater eggs. There were multiple and significant differences in the fatty acids between eggs from the two groups, but there was no difference for vitellin (Vn). The levels of phosphorus (P), magnesium (Mg), vitamin A (VA) and vitamin E (VE) in wild eggs were significantly higher than in freshwater eggs, but calcium (Ca) and zinc (Zn) levels did not differ between the two groups. These results can be used to discriminate wild eggs and reconditioned eggs. Also suggested is to decrease lipids and increase protein levels in freshwater eggs for better egg quality. Mg, P, VA and VE should also be given as sturgeon food supplements.
      PubDate: 2014-08-13T07:38:28.871246-05:
      DOI: 10.1111/jai.12547
       
  • Non‐lethal gill biopsy of juvenile hybrid sturgeon (Acipenser
           ruthenus ♀ × A. schrenckii ♂): validity
           and impact on growth and osmoregulation
    • Authors: F. Zhao; P. Zhuang, T. Zhang, L. Zhang, J. Liu, J. Hou
      First page: 1243
      Abstract: The objective of this study was to validate a gill biopsy method for non‐lethal monitoring of the osmoregulatory status of young sturgeon in estuary areas. After gill biopsy, hybrid sturgeon (Acipenser ruthenus ♀ × A. schrenckii ♂) were transferred from freshwater to brackish water (10 ppt) for 6 weeks. Mortality, serum osmolality, ion concentrations and gill Na+, K+‐ATPase activity of fish exposed to brackish water was measured. No detrimental effects on subsequent survival, growth or osmoregulation of hybrid sturgeon were observed.
      PubDate: 2014-08-18T07:55:32.431904-05:
      DOI: 10.1111/jai.12554
       
  • A review of the structure of sturgeon egg membranes and of the associated
           terminology
    • Authors: M. A. M. Siddique; J. Cosson, M. Psenicka, O. Linhart
      First page: 1246
      Abstract: Knowledge of the morphological properties, species specific differences, development, and function of the sturgeon egg envelope is of importance for a better understanding of sturgeon reproduction as well as for improvement of the caviar quality. The structure of the egg envelope is similar among the various species, comprising an external envelope (thecal cells, basal lamina, and follicular epithelium), a five‐layered oocyte envelope (adhesive layer, alveolar layer, epilayer, and zona radiata externa and interna) and a layer of oocyte matrix and cortical granules. Egg diameters (1.5–4.9 mm), structure and number of the micropyles (2–52), and the size of the micropylar field distinguish eggs of the various species. The development of the egg envelope within the ovary comprises five stages, with further changes following fertilization with the formation of a fertilization cone. The mechanism of polyspermy block in sturgeon eggs and the role of the micropyle and cortical granules in polyspermy block are also described in this review. This review provides information on the morphology and the developmental stages of the egg envelope that will further the understanding of egg biology of acipenserid species. Standardization of terminology describing the egg envelope would minimize confusion and be helpful for future work on acipenserid eggs.
      PubDate: 2014-09-15T03:04:57.567845-05:
      DOI: 10.1111/jai.12604
       
  • The effect of essential fatty acid (EFA) enrichment of Artemia sp. nauplii
           on the enzymatic activity of Atlantic sturgeon (Acipenser oxyrinchus
           Mitchill, 1815) larvae – preliminary study
    • Authors: M. Kamaszewski; M. Wójcik, T. Ostaszewska, R. Kasprzak, R. Kolman, M. Prusińska
      First page: 1256
      PubDate: 2014-08-23T02:30:34.482873-05:
      DOI: 10.1111/jai.12561
       
  • Effect of temperature and substrate on whole body cortisol and size of
           larval white sturgeon (Acipenser transmontanus Richardson, 1836)
    • Authors: L. C. Bates; M. A. Boucher, J. M. Shrimpton
      First page: 1259
      Abstract: White sturgeon (Acipenser transmontanus Richardson, 1836) larvae were reared at two temperatures (13.5 or 17.5°C) with or without gravel as a substrate to examine the effect of rearing environment on growth and whole body cortisol, an index of stress (initial weight 23.4 mg; four replicate tanks per treatment). Larvae were sampled 8, 16, and 24 days post‐hatch. Larvae were larger when reared with substrate and at warmer temperatures. For whole body cortisol, a significant age by temperature interaction was observed with the highest values on day 16 for larvae from warm water treatments. Larvae reared in gravel consistently showed significantly lower whole body cortisol than larvae reared without substrate. In response to mechanical agitation, there was a significant effect of time following disturbance. Increased growth and reduced stress hormone levels make substrate rearing of yolksac larvae an important technique for enhancement efforts in artificial and natural environments. The positive effects of temperature on growth, however, with higher whole body cortisol, suggest that larval white sturgeon development may be better at cooler temperatures.
      PubDate: 2014-08-19T01:08:41.777671-05:
      DOI: 10.1111/jai.12570
       
  • Early development and allometric growth patterns of beluga Huso huso
           (Linnaeus, 1758)
    • Authors: E. Gisbert; R. Asgari, Gh. Rafiee, N. Agh, S. Eagderi, H. Eshaghzadeh, C. Alcaraz
      First page: 1264
      Abstract: Hatchery reared beluga (Huso huso) were observed from hatching until the juvenile stage in order to analyse their early development and allometric growth patterns using bivariate and multivariate allometric analyses for different body regions (e.g. head, trunk, tail) and test whether there existed similarities in the growth patterns of beluga compared to other fish species, especially other sturgeon species belonging to the genus Acipenser. Results from Principle Component Analysis on morphometric characters (total length, head length, head height, trunk length, rostrum length and eye diameter) in specimens showed that there were shifts in the relative growth of these characters in early development (length at metamorphosis, Lm). A first stage comprised of hatching to 17.03 ± 0.14 mm in total length (Lm1), a second stage was between 17.03 and 25.41 ± 0.21 mm (Lm2), and a third developmental stage at larger sizes (larvae larger than Lm2). Most morphological (feeding, swimming, sensorial and respiratory systems) and morphometric changes in beluga development took place during the second growth stanza, which may be considered as a transitional period from the larval to the juvenile stage, whereas at larger sized fish may be considered as early juveniles. The allometric growth of beluga matched developmental and behavioral events (e.g. swimming‐up, schooling and free benthic swimming) observed in the early ontogeny of this species, and showed the priority of growth of the cephalic and tail regions in beluga pre‐larvae for feeding and respiratory functions, and the tail for cruising and escape reactions prior to the full development of the digestive system. This study provides information on the ontogeny of the species, establishing a reference for its normal development that might be useful for evaluating the suitability and quality of fish produced for restocking purposes and improving the current beluga management plans.
      PubDate: 2014-11-06T02:32:14.560203-05:
      DOI: 10.1111/jai.12617
       
  • An AFLP‐based approach for the identification of sex‐linked
           markers in Amur sturgeon Acipenser schrenckii Brandt, 1869
    • Authors: T.‐Q. Xiao; C.‐Y. Lu, C. Li, L. Cheng, D.‐C. Cao, X.‐W. Sun
      First page: 1282
      Abstract: Sturgeon species are widely known for their caviars. A large part of the expense associated with caviar production is due to the length of time individuals must be reared before reaching maturity. Sex identification at an early age would reduce costs of broodstock rearing. A DNA AFLP‐fingerprinting approach was used to identify sex‐specific markers and sex‐associated markers that exhibit a difference between female and male Amur sturgeon Acipenser schrenckii Brandt, 1869. AFLP analysis of six females and six males using 64 primer combinations yielded a total of 7116 AFLP bands of which 1264 (17.76%) bands were polymorphic. The polymorphism exhibited differences between female (15.64%) and male (16.34%) groups. Sex‐specific markers were not detected among the AFLP bands. However, 42 presumed sex‐associated bands that exhibited large differences between females and males were identified in 34 primer combinations. None of the 28 SCAR markers derived from the 39 sequences exhibited sex specificity when tested against 15 females and 15 males. Nevertheless, five SCAR markers exhibited a significant difference between the sexes. Sequence analysis using blastn in GenBank revealed high homology for 10 fragments, among which C4 was associated with the secretion of prolactin in mammals, but was not sex‐specific based on testing of SCAR markers. The five SCAR markers and the clone C4 may represent candidate genes for future research of sex specificity.
      PubDate: 2014-08-18T07:45:35.924163-05:
      DOI: 10.1111/jai.12553
       
  • Genetic estimation of evolutionary and contemporary effective population
           
    • Authors: C. C. Wilson; J. L. McDermid, K. M. Wozney, S. Kjartanson, T. J. Haxton
      First page: 1290
      Abstract: The potential of sturgeon species and populations to adapt to current challenges and changing conditions will depend on their adaptive resources and capacity, which can be inferred from their genetic effective population size (Ne). Existing microsatellite genetic data from published studies were used to estimate Ne of lake sturgeon (Acipenser fulvescens) across hierarchical spatial and temporal scales. Previous analysis of mitochondrial DNA data suggested that the species has an evolutionary female effective population size (Nef) of ~8000, substantially lower than other North American freshwater fish species with similar distributions. Phylogeographic data were used to reconstruct the genetic makeup and diversity of phylogeographic lineages, and compare the genetic diversity and Ne of contemporary Canadian populations to their ancestral founding populations. A similar approach was used to estimate ancestral Ne for fragmented populations in formerly continuous habitats. On the finest spatiotemporal scale, point estimates of Ne for sturgeon populations in contiguous river fragments were compared against Ne values from reconstructed ancestral (pre‐fragmentation historical) populations to assess changes in Ne since fragmentation occurred. These results illustrate the versatility of genetic data for estimating historical demographics of sturgeon, as well as providing information on their adaptive potential and long‐term sustainability if given the ecological opportunity.
      PubDate: 2014-11-27T05:59:52.972012-05:
      DOI: 10.1111/jai.12615
       
  • Forensic investigations into a GenBank anomaly: endangered taxa and the
           importance of voucher specimens in molecular studies
    • Authors: C. B. Dillman; P. Zhuang, T. Zhang, L.‐Z. Zhang, N. Mugue, E. J. Hilton
      First page: 1300
      Abstract: Whole mitochondrial genome (mitogenome) sequences provide a powerful approach for investigating and hypothesizing relationships at a broad range of phylogenetic levels, and these data have been used extensively across the diversity of fishes. Mitogenome sequence studies have typically used an exemplar approach wherein one individual is sampled and sequenced. However, as more laboratories are producing these data, taxon sampling within clades, including within‐species sampling, is naturally increasing. There are currently eleven acipenserids with complete mitogenome sequences available for download and use from GenBank. Exploration of these sequences indicates that the mitogenome for Acipenser sinensis, the Chinese sturgeon, may either be incorrectly identified or the result of undocumented hybridization with A. gueldenstaedtii. Recently, new material with vouchered specimens has been collected and investigated with DNA sequence data from four mtDNA loci to test whether the published mitogenome of A. sinensis was recovered in the same clade with the new vouchered material. This example reinforces the need for voucher specimens and materials for genetic sequence data.
      PubDate: 2014-09-06T02:23:55.803371-05:
      DOI: 10.1111/jai.12568
       
  • Current status of feeding stocks of the kaluga sturgeon Huso dauricus
           Georgi, 1775, and Amur sturgeon Acipenser schrenckii Brandt, 1889, in
           Russian waters
    • Authors: V. Koshelev; A. Shmigirilov, G. Ruban
      First page: 1310
      Abstract: Biological parameters of the kaluga Huso dauricus and Amur Acipenser schrenckii sturgeons have been analyzed in their foraging areas in Russian waters. Results show that both species are now sufficiently abundant only in catches from the lower Amur River, its mouth, and the Amur Estuary. The largest Amur sturgeon individuals occur in the estuary, while the largest kaluga sturgeon reside in the estuary as well as in the Sea of Okhotsk. Catches made in the river consist mainly of juvenile fish. The average body sizes of kaluga and Amur sturgeons in catches from the lower Amur River and the Amur Estuary have decreased significantly compared to records from 1929 to 1930. Between 2006 and 2011, the proportions of mature kaluga and Amur sturgeons in the river catches averaged 2.9 and 5.1%, respectively, and at its mouth and in the estuary by 42.6 and 32.8%, respectively. Abundance of kaluga sturgeon (age >1 year) in the lower Amur and the estuary in 2011 reached 345 000 individuals at a biomass of 7110 tonnes (t). Abundance of Amur sturgeon (age >1 year) in the same area and time reached 289 000 individuals at a biomass of 1946 t. The main stocks of the respective species (324 300 individuals or 94% in Kaluga, 263 570 individuals or 91.2% in Amur sturgeon) are concentrated in the Amur Estuary. To restore their populations in the Amur, a ban on all types of commercial fishing at the spawning grounds and juvenile foraging grounds should be implemented. It is also necessary to increase the number of hatchery‐reared juveniles and allow them to grow to a greater body size before release into the Amur.
      PubDate: 2014-09-26T07:12:54.991772-05:
      DOI: 10.1111/jai.12606
       
  • Using mark‐recapture data in an individual‐based model to
           evaluate length‐at‐age differences between two Snake River
           white sturgeon (Acipenser transmontanus Richardson, 1836) populations in
           Idaho, USA
    • Authors: P. Bates; J. Chandler, K. Lepla, K. Steinhorst
      First page: 1319
      Abstract: Despite showing similar abundance estimates, population surveys of wild white sturgeon (Acipenser transmontanus Richardson, 1836) in the Bliss and Hells Canyon reaches of the Snake River display very different stock structures. To better understand these differences, an individual based model was developed using empirical mark‐recapture metrics from 343 white sturgeon recaptured in the Bliss reach [at‐large 1.0–19.9 years], and 580 white sturgeon recaptured in the Hells Canyon reach [at‐large 1.0–21.2 years]. After calculating annual growth increments from these recaptures, individuals from each reach were assigned to size bins then randomly chosen from within each bin to ‘grow’ theoretical fish. This process was bootstrapped 1000 times, producing a mean length‐at‐age trajectory for each reach. From these data, mark‐recapture samples were assigned estimated ages and fitted to a three‐parameter logistic growth curve. Results indicate a wide disparity in length‐at‐age of white sturgeon between reaches, with the Bliss population displaying an intrinsic rate of increase [K = 0.118] twice that of the Hells Canyon population [K = 0.059]. This is due primarily to slow juvenile growth in the Hells Canyon population relative to juvenile growth in the Bliss population. The much slower growth rate of juveniles in the Hells Canyon reach has consequences to population demographics, such as age at first maturity. Although growth differences are large, both populations appear to be stable or increasing in abundance despite being regulated by very different mechanisms.
      PubDate: 2014-08-25T04:57:12.015752-05:
      DOI: 10.1111/jai.12557
       
  • Identification of a robust Lake Sturgeon (Acipenser fulvescens Rafinesque,
           1917) population in Goulais Bay, Lake Superior
    • Authors: T. C. Pratt; W. M. Gardner, J. Pearce, S. Greenwood, S. C. Chong
      First page: 1328
      Abstract: Lake Sturgeon (Acipenser fulvescens Rafinesque, 1917) in Lake Superior are greatly depressed from their historic abundance, and few populations meet the rehabilitation goals identified by management agencies. A netting program targeting juvenile Lake Sturgeon (ages 3–15) was implemented from 2010 to 2012 in Goulais Bay, a shallow, productive bay in the south‐eastern part of the lake, to determine abundance, distribution, population characteristics (size structure, condition, age structure, mortality and growth), and recruitment patterns. Five‐hundred and thirty‐one individuals were captured over the 3‐year study, resulting in a mark‐recapture estimate of 4977 (95% CIs 3295–7517) juveniles. Catch rates in this study were higher than in any other location in Lake Superior, with sturgeon being broadly distributed around the bay. Estimated annual survival rate ranged from 0.691 to 0.858, depending on the method used. The majority of fish captured were between 620 and 800 mm in total length and were between 4 and 10 years of age (range 1–29 years). Recruiting year‐classes were apparent every year, with no apparent effects due to lampricide treatments (a suspected threat to age‐0 Lake Sturgeon) in the Goulais River. Year‐class strength was positively related to spring water levels. It is possible that this robust Goulais Bay population could help re‐populate the south‐eastern part of Lake Superior, which contains a number of large, productive embayment areas that formerly supported large Lake Sturgeon populations.
      PubDate: 2014-08-19T01:08:59.291922-05:
      DOI: 10.1111/jai.12566
       
  • Variation in lake sturgeon (Acipenser fulvescens Rafinesque, 1817)
           abundance in rivers across Ontario, Canada
    • Authors: T. Haxton; M. Friday, T. Cano, C. Hendry
      First page: 1335
      Abstract: The objectives of this study were to (i) assess the variation in relative abundance of lake sturgeon (Acipenser fulvescens Rafinesque, 1817) subjected to various man‐induced stresses and physical characteristics at a landscape scale across Ontario; and (ii) ascertain the factors that explain the variability observed among rivers using a multivariate approach. A standardized index netting program targeting juvenile and adult Lake Sturgeon was conducted over two field seasons at 22 river sites across Ontario. Each river had unique or different human‐induced stresses and physical characteristics. Relative abundance of Lake Sturgeon varied in river across the Ontario landscape. A principal component analysis was conducted using site physical characteristics with the associated anthropogenic stressors. The catch‐per‐unit‐effort (CPUE) for juvenile and adult Lake Sturgeon were then regressed with the scores of principal components having eigenvalues >1. The variation observed was best explained by the negative relationship observed between CPUE and the presence of hydroelectric generating stations. Historical commercial fisheries also had an effect on Lake Sturgeon abundance whereas subsistence fisheries seemed to focus on rivers that were not regulated and where Lake Sturgeon numbers were greater. Research and recovery efforts should focus on minimizing the impact of hydroelectric generation on Lake Sturgeon while achieving socioeconomic goals.
      PubDate: 2014-08-23T02:29:40.660359-05:
      DOI: 10.1111/jai.12550
       
  • Validation of a methodology to determine female white sturgeon (Acipenser
           transmontanus Richardson, 1836) habitat use within a riverscape during the
           spawning season
    • Authors: V. L. Paragamian; P. Rust
      First page: 1342
      Abstract: The objective was to use hydrologic and bathymetric models for the riverscape of the Kootenai River, Idaho, USA and integrate these data with radio telemetry locations of two female white Sturgeon, Acipenser transmontanus Richardson, 1836, during the spawning season. The detailed analysis of habitat features and models provided an enhanced understanding of the habitat preferences of spawning White Sturgeon, which could be used to protect or enhance the habitat. Hydrologic models will also provide a basis to incorporate a larger sample of fish in the future. The White Sturgeon habitats were studied during the 2002 and 2003 spawning seasons. Depth sensitive radio transmitters, geographic positioning systems, single‐beam and multibeam echo sounders and multidimensional surface water modeling were used to identify similarities and dissimilarities in the habitat selection of the two monitored female White Sturgeon. The movements of the two fish were not randomly distributed; both fish spent a significant amount of time swimming near the river bottom and thalweg or resting near the river bottom (within 20% of the lower water column [6–9 m]). Mahalanobis distances quantitatively described the similarities between select habitat features of depth, river velocity and riverbed slope at the studied locations and compared the entire spawning reach. The fish occupied sites previously identified as spawning locations. Both fish selected similar depth, median velocity (0.3 m s−1) and bank preferences, avoiding the shallow water on the inside of meander bends and tending to stay in the deeper water on the outside of meanders. They exhibited a tendency to occupy intermediate velocities in parts of the river where the ratio of the velocity at the fish to the maximum velocity in the channel cross‐section was >0.25 and
      PubDate: 2014-09-16T23:44:21.647658-05:
      DOI: 10.1111/jai.12571
       
  • Population size of pallid sturgeon, Scaphirhynchus albus (Forbes &
           Richardson, 1905), in the lower Missouri River near Kansas City, Missouri,
           USA
    • Authors: K. R. Winders; K. D. Steffensen
      First page: 1356
      Abstract: The objectives of this study were to investigate the population size of hatchery‐reared and wild pallid sturgeon, Scaphirhynchus albus (Forbes & Richardson, 1905), in a 43.3 river kilometer (rkm) reach of the Missouri River downstream of Kansas City, Missouri, USA and compare these with previous published estimates. This reach has been shown to represent the abundance and distribution of the pallid sturgeon population throughout the lower Missouri River, and was therefore chosen for this study in order to monitor progress towards recovering this federally endangered species. The robust‐design approach was used within the Program MARK using mark‐recapture data of fish sampled from 2011 to 2013. The annual population estimates of pallid sturgeon varied from 6.1 to 11.1 fish/rkm, of which known hatchery‐origin pallid sturgeon (5.5 to 10.2 fish/rkm) were much more abundant than those of wild origin (0.6 to 0.9 fish/rkm). These population estimates are drastically fewer than those published for another reach of the lower Missouri River and represent far less advancement (12–18%) towards meeting the five wild adult fish/rkm criteria for considering reclassification of pallid sturgeon.
      PubDate: 2014-08-19T01:10:26.110624-05:
      DOI: 10.1111/jai.12558
       
  • Population characteristics of pallid sturgeon, Scaphirhynchus albus
           (Forbes & Richardson, 1905), in the lower Platte River, Nebraska
    • Authors: M. J. Hamel; M. A. Pegg, J. J. Hammen, M. L. Rugg
      First page: 1362
      Abstract: Pallid sturgeon, Scaphirhynchus albus (Forbes & Richardson, 1905), have been studied intensively in recent years to understand a declining adult population that does not seem to be naturally reproducing; however, most of this effort has occurred in the main‐stem Missouri and lower Mississippi rivers. Pallid sturgeon are known to occupy tributary streams intermittently, but the importance of tributaries for completion of essential life stages for pallid sturgeon remains unknown. Tributaries may provide uses for fish spawning and reproduction, nursery or refuge habitat, and areas for foraging. Therefore pallid sturgeon population characteristics were studied in the Platte River, Nebraska, a large tributary to the Missouri River. During 2009–2012 137 pallid sturgeon were captured. Pallid sturgeon were found throughout the lower 159 km of the Platte River throughout the entire year (March–November); however, pallid sturgeon were more abundant in the lower‐most 52 km during 2009 and 2010. Capture locations were in comparatively deeper water along flow gradients between the thalweg and mid‐channel sandbars. Most pallid sturgeon were of hatchery origin and dispersed an average of 197.5 km (±233 SD) from the original stocking location to the Platte River capture site. Although the direct reasons for are unknown, the lower Platte River may be providing habitat or resources that are not typically found in the channelized Missouri River. Continued research in the Platte River and other large tributaries may provide insight for recovery of endemic, large‐river species. Persistence of large‐river fishes may depend on population connectivity at multiple scales; identifying these connections is critical.
      PubDate: 2014-08-22T05:27:28.83838-05:0
      DOI: 10.1111/jai.12560
       
  • Historical biomass and sustainable harvest of Great Lakes lake sturgeon
           (Acipenser fulvescens Rafinesque, 1817)
    • Authors: T. Haxton; G. Whelan, R. Bruch
      First page: 1371
      Abstract: Historical abundance and biomasss of lake sturgeon (Acipenser fulvescens Rafinesque, 1817) in the Great Lakes were estimated from historical commercial harvest data from 1879 to 1920 using two modeling techniques: a surplus production model with a Bayesian approach, and a depletion model. In addition, theoretical sustainable levels of exploitation and temporal recovery periods were estimated based on the surplus production model. The historical biomass of Lake Sturgeon in the Great Lakes during the period from 1879 to 1885 varied for each model and ranged from 313 900 to 6 473 000 kg (0.5–16.7 kg ha−1) using the surplus production model to 968 000 to 25 414 000 kg (2.4–31.7 kg ha−1) using the depletion model. The intrinsic population growth rate as determined from the surplus production model ranged from 0.079 to 0.123, and the theoretical sustainable exploitation rate ranged from 2.0 to 3.1%. The predicted recovery period for the overexploited populations was in excess of 60 years given recruitment assuming all other impediments to population recovery were removed.
      PubDate: 2014-08-25T04:46:10.195223-05:
      DOI: 10.1111/jai.12569
       
  • Modelling attempts utilized in sturgeon research: a review of the
           state‐of‐the art
    • Authors: I. Jarić; J. Gessner, M.‐L. Acolas, P. Lambert, E. Rochard
      First page: 1379
      Abstract: The objective of this paper was to understand trends in modelling over time within sturgeon research and the effects of modelling applications on the scientific community using a bibliometric approach on articles from the ISI Web of Knowledge online database between 1996 and 2012. The results indicate an increasing contribution of modelling within the general field of sturgeon research. The population models analyzed mainly focused upon the impacts of fisheries, dams, stocking, genetics and elasticity/sensitivity analyses. Habitat suitability models, hydrodynamic models, bioenergetic models and general statistical models focused on the effects of habitat availability, species distribution, survival, growth and spawning migrations. The largest number of publications originated from North America, with a regional focus on the West Coast and Mississippi/Great Lakes regions. In contrast, model development and application was lacking for the Aral Sea region and Siberia. Moreover, thus far there were no published population models for north‐western European and Mediterranean sturgeon populations. The models have only been applied to a limited number of species and, with an increased Red List status of a species, the number of publications decreased substantially. Such results should be considered as a warning sign with regard to the effective implementation of conservation strategies for endangered species, given that the development of models is considered a key tool for the optimization of management and protection measures.
      PubDate: 2014-09-06T02:23:38.622874-05:
      DOI: 10.1111/jai.12572
       
  • Status and management of lake sturgeon (Acipenser fulvescens Rafinesque,
           1817) in the upper St. Croix River and Namekagon River, Wisconsin, USA
    • Authors: J. Kampa; G. Hatzenbeler, M. Jennings
      First page: 1387
      Abstract: The upper St. Croix River and Namekagon River have been managed with a closed lake sturgeon (Acipenser fulvescens Rafinesque, 1817) fishing season since 1994. Lake Sturgeon abundance and distribution have not been assessed above the confluence of the two rivers since this regulation was established. We documented abundance, distribution and movement of the Lake Sturgeon in both rivers from their confluence upstream to the first dam on each river during 2008–2012. Captured with boat‐mounted direct current electrofishing and by hook and line, 136 sturgeon ranging from 37 cm to 140 cm total length were tagged. Annual electrofishing catch was only 6% of the catch during the 1960s on a 32 km reach of the Namekagon River. Size structure showed that recruitment was significantly higher during the 1960s in the Namekagon River. Lake Sturgeon movement between rivers was documented during both sampling periods with direct line movements of >80 km. While still depressed, the A. fulvescens population below the first dam upstream from the confluence of the Namekagon River and the upper St. Croix River is naturally recruiting and appears to have the potential to restore itself with a closed fishing season.
      PubDate: 2014-07-30T05:33:08.10332-05:0
      DOI: 10.1111/jai.12541
       
  • Verifying success of artificial spawning reefs in the St.
           Clair–Detroit River System for lake sturgeon (Acipenser fulvescens
           Rafinesque, 1817)
    • Authors: E. K. Bouckaert; N. A. Auer, E. F. Roseman, J. Boase
      First page: 1393
      Abstract: Lake sturgeon (Acipenser fulvescens) were historically abundant in the St. Clair – Detroit River System (SCDRS), a 160 km river/channel network. In the SCDRS, lake sturgeon populations have been negatively affected by the loss/degradation of natural spawning habitat. To address habitat loss for lake sturgeon and other species, efforts are underway to restore spawning substrate by constructing artificial reefs. The main objective of this study was to conduct post‐construction monitoring of lake sturgeon egg deposition and larval emergence near two of these artificial reefs: Fighting Island Reef (FIR) in the Detroit River, and Middle Channel Reef in the St. Clair River. An additional site in the St. Clair River where lake sturgeon spawn on a coal clinker bed was also investigated. From 2010 to 2012, viable eggs and larvae were collected from all of these reefs, indicating that conditions are suitable for egg deposition, incubation, and larval emergence. In the St. Clair River, the results indicate the likelihood of other spawning sites upstream of these artificial reef sites.
      PubDate: 2014-09-24T04:03:37.065905-05:
      DOI: 10.1111/jai.12603
       
  • How to sample juvenile Lake Sturgeon, (Acipenser fulvescens Rafinesque,
           1817), in Boreal Shield rivers using gill nets, with an emphasis on
           assessing recruitment patterns
    • Authors: C. A. McDougall; C. C. Barth, J. K. Aiken, L. M. Henderson, M. A. Blanchard, K. M. Ambrose, C. L. Hrenchuk, M. A. Gillespie, P. A. Nelson
      First page: 1402
      Abstract: Adaptive management and recovery initiatives for long‐lived, late‐maturing species such as Lake Sturgeon, Acipenser fulvescens, are complicated by temporal lags. By the time anthropogenic impacts on critical periods (spawning, larval hatch, age‐0 survival) would be manifested in adult populations, decades might have passed. However, recruitment patterns and population trajectory responses (both positive and negative) can be identified by examining the juvenile life stage. This study describes and evaluates a gill net method for sampling juvenile Lake Sturgeon between 250 and 800 mm fork length (FL) resident in Boreal Shield rivers in relative proportion to their abundance. The method is based on previous observations of deepwater preference (>10–15 m), and employs mesh sizes of 25.4, 50.8, 76.2, 127.0 and 152.4 mm stretched measure. Selectivity curves were generated based on 1040 Lake Sturgeon captures from six reaches of the Winnipeg and Nelson rivers, Canada. A normal (common spread) curve approximated a normal distribution centered on ~390 mm FL, and relative selection exceeded 0.65 across the 250–800 mm FL range. For the Slave Falls Reservoir (Winnipeg River), Spearman's rank‐order correlation (ρ) for zone‐specific cohort‐frequency distributions in adjacent sampling years ranged from 0.85 to 0.93, while the score for the entire reservoir was 0.95, suggesting inter‐annual consistency. The method allows for rapid and robust assessments of relative abundance and cohort strength for juvenile Lake Sturgeon within large Boreal Shield river systems, and facilitates biological comparisons among reaches and over time. Incidentally, cohort frequency results derived herein indicate that juvenile recruitment in regulated Boreal Shield rivers can be erratic, irrespective of size of the spawning stock. Such a pattern could be an inherent characteristic of the species that needs to be accounted for when developing adaptive management and species recovery plans.
      PubDate: 2014-09-22T02:11:48.863949-05:
      DOI: 10.1111/jai.12581
       
  • The need for genetic support in restocking activities and ex situ
           conservation programmes: the case of the Adriatic sturgeon (Acipenser
           naccarii Bonaparte, 1836) in the Ticino River Park
    • Authors: E. Boscari; L. Congiu
      First page: 1416
      Abstract: The Adriatic sturgeon (Acipenser naccarii Bonaparte, 1836), endemic to the North Adriatic region, was recently reclassified by IUCN as ‘Critically endangered and possibly extinct in the wild’ since no natural spawning has been recorded in the last 20 years. Its survival relies on restocking activities originating from a single captive broodstock collected by a private aquaculture plant (V.I.P.) in the 1970s and is currently reduced to 13 individuals. Few alternative brood‐stocks of F1 animals have been retained for use in the near future. Thus far, brood‐stocks, as well as all stocks released in the wild, have been randomly chosen without regard to their genetic composition. The consequence of breeding programmes with no genetic input was evaluated in the Ticino River Park (TRP) in Italy. A parental allocation procedure based on microsatellite markers useful for tetraploids was used following a Band‐Sharing approach. Levels of relatedness within the TRP F1 captive breeders (Stock_1) and among animals released by TRP in the past (Stock_2) were explored and compared with the stock of wild origin. The pronounced decrease in genetic diversity observed in the analysed sample suggests the need for complete reorganization and coordination of conservation efforts for this species, paying particular attention to the long‐term preservation of the genetic diversity. Also identified is the only potentially suitable stock of F1 animals that should be used as source of future breeders.
      PubDate: 2014-08-02T01:08:27.428554-05:
      DOI: 10.1111/jai.12545
       
  • Initial evaluation of the release programme for Dabry's sturgeon
           (Acipenser dabryanus Duméril, 1868) in the upper Yangtze River
    • Authors: J. M. Wu; Q. W. Wei, H. Du, C. Y. Wang, H. Zhang
      First page: 1423
      Abstract: This paper evaluates the outcome of the first release programme for Acipenser dabryanus rehabilitation in its natural habitat and focuses specifically on the growth rate of released juveniles, and on the dispersal of the fish after release. To conserve and restore natural recruitment, the conservation propagation programme has released hatchery‐reared juveniles annually in the upper Yangtze River. This paper summarized the release activities and analysed post‐release monitoring data. From 2010 to 2012, 7030 juveniles aged 1–3 years were released in the Shuifu and Yibin reaches of the upper Yangtze River. Incidental catches of 112 samples were recorded during the three‐year observation period. Recapture sites were located between Yibin and Chongqing reaches (approximate range of 385 km), with 72.3% of the individuals recaptured within 20 km from the release site. Incidental catches were mainly in shallow water within 20 m of the riverbank. Body weight of the released sturgeon initially declined but this lost weight was soon regained. The low recaptured rate indicates that only a few of the released juveniles were able to survive and settle in the upper Yangtze River. The observed movement patterns suggest a potential additional downstream release site for future consideration to improve the performance of the released fish.
      PubDate: 2014-09-29T01:28:56.801636-05:
      DOI: 10.1111/jai.12597
       
  • Survival of hatchery Gulf sturgeon (Acipenser oxyrinchus desotoi Mitchill,
           1815) in the Suwannee River, Florida: A 19‐year evaluation
    • Authors: K. J. Sulak; M. T. Randall, J. P. Clugston
      First page: 1428
      Abstract: An experimental release of 1192 hatchery‐reared, individually PIT tagged, 220 days old (296–337 mm TL) Gulf sturgeon, Acipenser oxyrinchus desotoi, was undertaken in 1992 in the Suwannee River, Florida. The original objectives of the 1992 release experiment were to: (1) evaluate survival rate of cultured Gulf sturgeon in the wild vs survival rate of their wild 1992 cohort counterparts, (2) determine the differential effect of release site within the river upon long‐term survival, and (3) evaluate comparative growth rates of recaptured hatchery vs captured wild 1992 cohort Gulf sturgeon. The present investigation addressed those original objectives, plus an additional fourth objective: (4) evaluation of hatchery fish recapture rate change over the 19‐year experiment. The primary objective was to determine efficacy of potential conservation aquaculture for this species in terms of long‐term survival in the wild. Follow‐up 1993–2011 gill net sampling in freshwater reaches (rkm 4–237) and the estuarine river mouth (rkm −6 to 4) yielded recaptures representing 13.0% of the total released. Mean annual hatchery fish mortality (including emigration) rate estimated for the 19‐year period (1993–2011) was more than twice that for same cohort wild fish. Mark‐recapture survival probability (phi) for hatchery fish, 1993–2011, was substantially lower (0.733) than for their wild counterparts (0.888). Mean annual hatchery fish recapture rate, as a percentage of all 1992 cohort fish recaptures, declined significantly after age‐7, coinciding with age of onset of migration into the open Gulf of Mexico. Hypothesized causal factors may be differentially lower fitness in the marine habitat or permanent outmigration due to natal river imprinting failure. Hatchery fish recapture rates varied significantly for fish from the ten release sites, being highest near the river mouth, and lowest for the furthest upriver sites in the Suwannee River and its Santa Fe River tributary. Hatchery fish also displayed a significantly lower growth rate than their wild counterparts through age 3000 days. Cumulative hatchery fish mortality of 99.87% over 19 years predicts
      PubDate: 2014-09-29T01:48:10.013584-05:
      DOI: 10.1111/jai.12607
       
  • Alarm cues in Lake Sturgeon Acipenser fulvescens Rafinesque, 1817:
           potential implications for life‐skills training
    • Authors: V. Wishingrad; J. R. Sloychuk, M. C. O. Ferrari, D. P. Chivers
      First page: 1441
      Abstract: An experiment was designed to investigate Lake Sturgeon (Acipenser fulvescens) responses to alarm cues and the ontogeny of anti‐predator behaviour in response to alarm cues in larval and juvenile sturgeon. A method for alarm cue preparation in larval sturgeon using full‐body homogenate and juvenile sturgeon using homogenized skin is described. Larval sturgeon in tanks exposed to alarm cues were shown to exhibit a dramatic increase in activity (e.g. an escape response) (t25 = 4.95, P 
      PubDate: 2014-09-10T23:51:50.532533-05:
      DOI: 10.1111/jai.12580
       
  • Improving swimming capacity of juvenile Dabry's sturgeon, (Acipenser
           dabryanus Duméril, 1869) in current‐enriched culture tanks
    • Authors: H. Du; Q.‐W. Wei, X. Xie, L.‐L. Shi, J.‐M. Wu, X.‐M. Qiao, Z. G. Liu
      First page: 1445
      Abstract: Swimming performance is one of the most important capacities for fish to cope with the harsh conditions in natural ecosystems and thus determines fitness of hatchery‐reared fishes for stocking in the wild. Poor swimming capabilities of hatchery‐reared fishes, including sturgeons, may be linked to the fact that the flow regimes in conventional culturing tanks are very often static and with very low currents, obviously differing from the natural environment. The objectives of the present studies were to: (i) learn about the swimming performance of the Dabry's sturgeon Acipenser dabryanus, one of the critically endangered species restricted to the Yangtze River, China; (ii) ascertain if it is possible to improve the swimming capacity of Dabry's sturgeon (DS) by changing the current flow regime in conventional culturing tanks; (iii) determine the potential effects of such an environmental enrichment practice on the growth and survival of DS. Long‐term culturing protocols with two culturing stages were conducted in a conventional tank with static water (Control, CT) as well as in a current‐enriched tank with a step‐controlled water velocity (CET). Results showed after the first culturing stage, which began with 500 15‐day‐old post‐hatch (dph) DS and ended with 40 dph DS, that the survival rates in CT (91.6%) were higher than that in the CET (84.4%). Total length, fork length and weight of DS in CET (n = 30) were higher than in CT (n = 30), but with no significant differences (P > 0.05). The Ucrit (13.2 ± 2.9 cm s−1, or 2.19 ± 0.48 FL s−1, n = 30) of the 40 dph DS in CET were significantly higher (10.2 ± 3.5 cm s−1, or 1.70 ± 0.59 FL s−1, n = 30) than in CT (P  0.05), whereas the Ucrit (48.5 ± 6.9 cm s−1, or 3.25 ± 0.46 FL s−1, n = 20) of the 80 dph DS in CET were also obviously higher (35.9 ± 8.5 cm s−1, or 2.41 ± 0.58 FL s−1, n = 20) in CT (P 
      PubDate: 2014-09-15T03:03:36.127837-05:
      DOI: 10.1111/jai.12591
       
  • Relative recruitment success of stocked age‐1 vs age‐0 lake
           sturgeon (Acipenser fulvescens Rafinesque, 1817) in the Nelson River,
           northern Canada
    • Authors: C. A. McDougall; D. J. Pisiak, C. C. Barth, M. A. Blanchard, D. S. MacDonell, D. Macdonald
      First page: 1451
      Abstract: Success of lake sturgeon (Acipenser fulvescens Rafinesque, 1817) stocking programmes has rarely been evaluated. As of the early 1990s, Lake Sturgeon populations were nearly extirpated from several sections of the upper Nelson River, Manitoba, at least in part due to historical overexploitation. Between 1994 and 2011, 20 885 fingerlings (age‐0, untagged) and 1117 yearlings (age‐1, 1014 PIT tagged) were stocked into an upper Nelson River reach. In fall 2012, a Lake Sturgeon population inventory using gill nets assessed post‐release survival/retention of stocked fish. Of 91 unique Lake Sturgeon captured, 67 (74%) possessed PIT tags, signifying they were stocked at age‐1. Relative recruitment success was conservatively estimated to be 17.7 times greater for age‐1 vs age‐0 stocked fish based only on PIT tag recapture data. However, including 19 additional fish identified as stocked at age‐1 based on atypical ‘first’ annuli patterns, the revised relative recruitment success rate was 130 times greater for age‐1 vs age‐0. An interpreted consensus ageing method produced correct age assignment 97% of the time for juveniles of known age, despite complications caused by overwinter growth in the hatchery.
      PubDate: 2014-08-30T03:32:02.860725-05:
      DOI: 10.1111/jai.12555
       
  • Swimming performance and larval quality are altered by rearing substrate
           at early life phases in white sturgeon, Acipenser transmontanus
           (Richardson, 1836)
    • Authors: D. W. Baker; D. S. O. McAdam, M. Boucher, K. T. Huynh, C. J. Brauner
      First page: 1461
      Abstract: To investigate the role of substrate enrichment on larval growth and performance, white sturgeon, Acipenser transmontanus, were reared for 12 dph (the pre‐feeding stage) in the presence and absence of enriched substrates (i.e. structurally complex media). Following this period, larval sturgeon were transferred to holding tanks with unenriched substrate (lacking structural complexity) and reared for an additional 30 days, during which time health and performance indicators (growth, Ucrit, startle response reaction time) and whole body lipid composition were assessed at 15 and 18°C. Sturgeon reared on unenriched substrates tended to grow more slowly (up to 40% reduced mass at 40 dph) with a lower condition factor (5–15% lower between 8 and 40 dph), but also exhibited delayed gut development and reduced rate of yolksac absorption (at 15 dph) than those reared with enriched substrates. Whole body lipid composition was significantly altered with substrate enrichment, although the biological relevance of these changes is unknown. White sturgeon reared without exposure to enriched substrates at some temperatures and developmental phases demonstrated modest reductions in aerobic (~20–30% lower Ucrit) and startle response performance (~5–10% slower reaction time) at 15 and 30 dph. Overall, most effects were influenced by rearing temperatures and parentage, such that differences were not statistically significant under all conditions. Clearly, however, substrate enrichment plays an important role in development of white sturgeon during early life stages.
      PubDate: 2014-11-27T05:59:19.502574-05:
      DOI: 10.1111/jai.12642
       
  • Estimating the potential for habitat restoration and connectivity effects
           on European sturgeon (Acipenser sturio L. 1758) population rehabilitation
           in a lowland river – the Havel, Germany
    • Authors: J. Gessner; S. Zahn, I. Jaric, C. Wolter
      First page: 1473
      Abstract: The intention of the paper is an evaluation of the restoration potential of the Spree‐Havel River system for rheophilic and anadromous fish species. The European sturgeon Acipenser sturio was used as an indicator species in the Spree‐Havel River system, focusing on the effects of providing longitudinal passage: (Scenario 1), and two possibilities for spawning site restoration (Scenario 2 = altered flow conditions below weirs and gravel addition, and Scenario 3 = fundamental riverbed modification to create spawning habitats). To determine the effects on population development, an age‐structured population model for A. sturio was used. Targets of the study were to predict potential effects of a Havel population on the Elbe River population, as well as to assess the effects of restoration and connectivity on the fish assemblage of the Spree‐Havel system, with special reference to the goals of the EU Flora‐Fauna‐Habitat Directive and the EU Water Framework Directive. The paucity of sturgeon caught in the Spree‐Havel River system during the 19th century indicates that alterations to the river system (mill weirs, flow alterations and communal wastes input) contributed to a significant population decrease. Restoration of the river connectivity alone will have little effect on its potential to support a sturgeon population without moderate improvements to the hydro‐morphology and habitat structures (scenario 2 = restoration of 30% of the potential habitats, resulting in 30 000 m2 of spawning habitat). This approach would increase the population potential dramatically when combined with the reestablishment of longitudinal connectivity up to Neuendorf Lake, which would reopen 220 km of river passage. As a result, the sturgeon population in the river system could contribute an estimated 41% to the potential total Elbe River population. The Spree‐Havel system has an estimated support potential of between 15 400 and 42 000 juvenile fish during out‐migration from the system and 4300–11 700 spawners for an annual return. Results of the modeling study confirm that the main restrictions to reach the WFD goals are associated with the lack of hydro‐morphological and hydro‐dynamic diversity in adjacent river stretches.
      PubDate: 2014-10-17T03:58:41.765874-05:
      DOI: 10.1111/jai.12613
       
  • Spatial distribution and habitat choice of adult Chinese sturgeon
           (Acipenser sinensis Gray, 1835) downstream of Gezhouba Dam, Yangtze River,
           China
    • Authors: H. Zhang; C. Y. Wang, D. G. Yang, H. Du, Q. W. Wei, M. Kang
      First page: 1483
      Abstract: Eight hydroacoustic surveys were conducted between 2007 and 2010 to determine the spatial distribution and habitat choice of adult Chinese sturgeon (Acipenser sinensis) within 85 km immediately downstream of Gezhouba Dam, which is the lower‐most dam blocking upstream sturgeon migration in the Yangtze River. A potential 32 A. sinensis were identified; depth, velocity, etc., characteristics were determined at the sturgeon site with an Acoustic Doppler Current Profiler. Most targets (26 individuals, 81.3%) were in water >12 m deep, and most (29 individuals, 90.6%) targets were near the river bottom. All targets stayed in or were close to the river channel (distance to the thalweg about one tenth of the river width). Fish were primarily distributed among four separate and deep areas. Variations in the water level played no significant role in fish distribution. Large, deep areas attracted the most fish. A preliminary analysis of environmental factors including water depth, flow velocity, Froude number and Reynolds number indicated that the bedform morphology (deep areas) was probably the key factor determining the A. sinensis habitat preference. Future conservation of the sturgeon will be more effective when special attention is given to the four refuges.
      PubDate: 2014-09-15T03:04:43.506718-05:
      DOI: 10.1111/jai.12589
       
  • Mechanical rock grinding in the Mississippi River: anthropogenic noise
           production and implications for the federally endangered pallid sturgeon,
           Scaphirhynchus albus (Forbes & Richardson, 1905)
    • Authors: G. L. Hempen; T. M. Keevin, M. T. Rodgers, B. M. Schneider
      First page: 1492
      Abstract: The use of mechanical rock grinding to remove rock pinnacles and outcroppings, considered to be navigation hazards in the Mississippi River, was evaluated as a less damaging alternative when compared to the more conventional use of drilling and blasting. The project area contains the federally endangered pallid sturgeon (Scaphirhynchus albus) and there was concern that intense sound pressure levels (SPLs) could impact the species. SPLs were measured during production rock grinding (January 2012, just north of Thebes, Illinois) and compared to those values with SPLs known to cause fish mortality, hearing damage, temporary hearing threshold shifts (TTS), and stress. The source SPLs’ maxima for each time block analyzed ranged from 160–172 dB (re 1 μPa @ 1 m) at frequencies ranging from 100–1250 Hz (1/3‐octave band). The highest source SPL maximum recorded for the sound recording session was 172 dB (re 1 μPa @ 1 m) at 1250 Hz. These SPL levels at 1 m from the grinder were well below levels responsible for mortality or noise induced hearing damage. The impact zone for stress (increases in cortisol) was calculated to be within a 9 m radius of the grinder, while the impact zone for TTS was calculated to be within 31 m of the grinder. Considering the small impact zones and continuous noise production during grinding, there is a strong possibility that sturgeon would either avoid or move out of the impact zone.
      PubDate: 2014-10-03T06:09:21.343349-05:
      DOI: 10.1111/jai.12582
       
  • Predicted effects of future climate warming on thermal habitat suitability
           for Lake Sturgeon (Acipenser fulvescens, Rafinesque, 1817) in rivers in
           Wisconsin, USA
    • Authors: J. Lyons; J. S. Stewart
      First page: 1508
      Abstract: The Lake Sturgeon (Acipenser fulvescens, Rafinesque, 1817) may be threatened by future climate warming. The purpose of this study was to identify river reaches in Wisconsin, USA, where they might be vulnerable to warming water temperatures. In Wisconsin, A. fulvescens is known from 2291 km of large‐river habitat that has been fragmented into 48 discrete river‐lake networks isolated by impassable dams. Although the exact temperature tolerances are uncertain, water temperatures above 28–30°C are potentially less suitable for this coolwater species. Predictions from 13 downscaled global climate models were input to a lotic water temperature model to estimate amounts of potential thermally less‐suitable habitat at present and for 2046–2065. Currently, 341 km (14.9%) of the known habitat are estimated to regularly exceed 28°C for an entire day, but only 6 km (0.3%) to exceed 30°C. In 2046–2065, 685–2164 km (29.9–94.5%) are projected to exceed 28°C and 33–1056 km (1.4–46.1%) to exceed 30°C. Most river‐lake networks have cooler segments, large tributaries, or lakes that might provide temporary escape from potentially less suitable temperatures, but 12 short networks in the Lower Fox and Middle Wisconsin rivers totaling 93.6 km are projected to have no potential thermal refugia. One possible adaptation to climate change could be to provide fish passage or translocation so that riverine Lake Sturgeon might have access to more thermally suitable habitats.
      PubDate: 2014-08-11T04:22:58.670483-05:
      DOI: 10.1111/jai.12543
       
  • Evaluating the genetic consequences of river fragmentation in lake
           sturgeon (Acipenser fulvescens Rafinesque, 1817) populations
    • Authors: J. L. McDermid; S. Nienhuis, M. Al‐Shamlih, T. J. Haxton, C. C. Wilson
      First page: 1514
      Abstract: Fragmentation of formerly continuous habitats can have significant consequences on subpopulations in isolated fragments. This study examined the temporal genetic consequences of historical river fragmentation by hydroelectric dams on lake sturgeon (Acipenser fulvescens Rafinesque, 1817), using temporal samples from two Ontario river systems. Temporal genetic analyses of samples from the Ottawa (dammed) and Kenogami (unregulated) river systems were used to (1) compare changes in genetic structure and diversity within and between free‐flowing and regulated systems; (2) assess how impoundments have influenced the spatial and temporal genetic structure and diversity within these contrasting systems; and (3) estimate effective population sizes (Ne) in both rivers using temporal genetic estimators. Levels of genetic diversity did not differ between impounded and free‐flowing rivers, nor did genetic diversity differ through time within a river system. Levels of genetic divergence over time were similarly minimal. We did, however, detect a 65% decline in effective population size in the impounded Ottawa River over two generations. Moreover, over the same time period the Ottawa River had substantially lower Ne estimates for Lake Sturgeon than the free‐flowing Kenogami River system. This study represents one of the first to observe genetic consequences of fragmentation on Lake Sturgeon. As such, this work reinforces the importance of maintaining or restoring habitat connectivity and availability for this migratory species, and mitigating other demographic threats that could compound, or be compounded by the effect of reduced genetic variation.
      PubDate: 2014-10-13T03:24:05.15858-05:0
      DOI: 10.1111/jai.12551
       
  • The effect of multi‐year vs single‐year stocking on lake
           sturgeon (Acipenser fulvescens Rafinesque, 1817) genetic diversity
    • Authors: A. B. Welsh; J. R. Jackson
      First page: 1524
      Abstract: Many lake sturgeon (Acipenser fulvescens Rafinesque, 1817) populations in the Great Lakes have not recovered from previous threats, whereby stocking can increase population abundances. Stocking in Oneida Lake, New York used two approaches: single‐year stocking using sturgeon from the Des Prairies River and multi‐year stocking using sturgeon from the St. Lawrence River. Stocked A. fulvescens were sampled and assigned to their corresponding stocking strategy based on age. Samples were analyzed at 12 microsatellite loci to evaluate how a single year of stocking (N = 273) and multiple years of stocking (N = 100) affected genetic diversity and effective population size (Ne). Single‐year stocking resulted in lower genetic diversity, likely due to a small number of parents. Multi‐year stocking retained most of the genetic diversity of the source population, compensating for the few parents available in a single year. Although multi‐year stocking resulted in a higher Ne, the Ne:N ratio was lower (0.34) compared to single‐year stocking (0.65), likely due to unequal sex ratios and family size variance across years. It is recommended that stocking of Lake Sturgeon take place over several years. However, consistent numbers need to be stocked each year and family size should be equalized across cohorts in order to maximize Ne.
      PubDate: 2014-08-02T01:08:31.620494-05:
      DOI: 10.1111/jai.12544
       
  • Comparing commercial and recreational harvest characteristics of
           paddlefish Polyodon spathula (Walbaum, 1792) in the Middle Mississippi
           River
    • Authors: R. N. Hupfeld; Q. E. Phelps
      First page: 1531
      Abstract: Here we contrast the relative influence of the commercial and recreational harvest sectors on the Middle Mississippi River paddlefish Polyodon spathula (Walbaum, 1792) population. We performed a creel survey of randomly selected commercial fishers and recreational anglers to gather characteristic harvest information to make comparisons between sectors. We found that the commercial sector harvested predominately large, mature paddlefish. Conversely, the recreational sector tended to harvest a greater proportion of small, immature paddlefish. Because these sectors are harvesting different portions of the population, the relative influence on the dynamic rate functions and potential conflict between sectors must be taken into account for fishery management decisions. One approach would be to increase the minimum length limit, to allow for equal harvest between the commercial and recreational harvest sectors. Ultimately, this will allow for both harvest sectors to harvest the same portion of the population, as well as increase the reproductive potential of the population. Additionally, obtaining an accurate assessment of the catch and effort for both sectors is imperative for the management and allocation of a shared resource.
      PubDate: 2014-08-07T02:20:20.962218-05:
      DOI: 10.1111/jai.12552
       
  • Present and future sturgeon and caviar production and marketing: A global
           market overview
    • Authors: P. Bronzi; H. Rosenthal
      First page: 1536
      Abstract: Continuous drastic declines in natural sturgeon populations over the past 30 years plus a high market demand for caviar have led the way for sturgeon farming, mainly for the production of caviar. Russia, Iran, members of the European Union, China and the USA were among the first; however, for the very same reasons countries outside the natural range of sturgeons also became involved (e.g. Uruguay, Arabian countries, Israel, and more recently Vietnam). At present (2012), the total caviar output from aquaculture is estimated at 260 tonnes, a production that could increase to 500–750 t within the next 10 years. If these figures are realistic, the future of caviar trade will be determined mainly by demand‐driven price structures, with the appearance of a new and evolving ‘mass market’ in addition to the traditional luxury high‐priced market. Other issues are the uncertainties and opportunities in the market place. All of these issues indicate that this relatively new branch of the aquaculture industry faces similar growing pains as in previous developments (e.g. salmon farming) but within a shorter time frame. The same drive that gave the incentive to farm sturgeons also provided, since the early 1970s, the incentives to seek alternative products that could fill the void in caviar supplies and even create new market sectors. The various products currently found on the market have been divided into six categories: (a) true caviar (using eggs from sturgeons); (b) substitute caviar (eggs derived from other fish species or from other animals); (c) imitation caviar (caviar‐like products constructed from other biological substances, imitating caviar in appearance and taste); (d) simulated caviar (produced by other biological substances to simulate only the taste of caviar, but not the appearance); (e) derivates (products that contain true caviar as a recipe component); (f) products with emotional associations to caviar (not related to caviar at all, but use the name as a marketing strategy to evoke a luxury image and infer a high value). At present, the eggs of more than 38 species of fish, besides sturgeons, and three species of other animals are used to produce substitutes. About 15 ‘caviar‐like’ preparations are used as raw materials – such as fish flesh, seaweed, and others mixtures. Five products can be considered simulations; few use caviar as a component in their production recipes. A variety of objects (unrelated to caviar) are currently marketed, but use ‘caviar’ in their trademark.
      PubDate: 2014-11-27T05:59:31.65886-05:0
      DOI: 10.1111/jai.12628
       
  • Sturgeon Aquaculture in China: status, challenge and proposals based on
           nation‐wide surveys of 2010–2012
    • Authors: L. Shen; Y. Shi, Y. C. Zou, X. H. Zhou, Q. W. Wei
      First page: 1547
      Abstract: At the end of 2012 and beginning of 2013, the authors conducted a nationwide survey of sturgeon aquaculture in China from 2010 to 2012. The survey results, combined with previous data, show that the dominant cultured species are Acipenser baerii, Huso dauricus♀ × A. schrenckii♂, A. baerii♀ × A. schrenckii♂, A. schrenckii, and A. gueldenstaedtii, accounting for 90% of the total production. Sturgeon farms have grown to include almost all provinces except Xizang, and are grouped principally in Shandong, Hubei, Sichuan and Chongqing, Beijing. The main culture systems are cage culture, and cement pond culture with running water. Sturgeon production rose from 34800 tonnes (t) in 2010 to 44500 t in 2012. The commercial sturgeon price dropped from 45 yuan per kg (5.5€/7.3$) in 2010 to 25 yuan per kg (3€/4$) in 2012. Nine caviar‐processing enterprises qualified for or were striving to process caviar, for a total production of 56.6 t caviar in 2012, of which 90% was exported. Major problems were also identified during the survey, including: disorderly hybridization and germplasm degradation; a stagnant domestic consumption demand; dramatic price fluctuations in different regions and at different times. Specialized sturgeon cooperatives had obtained government support to a certain extent, but did not use this to their advantage because of a lack of policy guidance and technical support. The processing of sturgeon products developed slowly. In view of the existing problems, certain proposals are discussed: publication of propagation standards, culture and processing to define the parental source of the commercial sturgeon and their by‐products; promulgate sturgeon consumption to expand market demand; establish a ‘Sturgeon Industry Association’ to constrain bad competition and cultivate good competitive mechanisms; build a protective pricing system to secure effectively the interests of some of the weaker farms; and conduct professional technical training courses on culture improvement and deep processing technology.
      PubDate: 2014-11-27T05:59:29.439543-05:
      DOI: 10.1111/jai.12618
       
  • Identification of genes involved in gonadal sex differentiation and the
           dimorphic expression pattern in undifferentiated gonads of Russian
           sturgeon Acipenser gueldenstaedtii Brandt & Ratzeburg, 1833
    • Authors: S. Hagihara; R. Yamashita, S. Yamamoto, M. Ishihara, T. Abe, S. Ijiri, S. Adachi
      First page: 1557
      Abstract: The establishment of a sexing technique at an early developmental stage is an important issue in sturgeon aquaculture, yet the mechanism of sex differentiation in sturgeons remains poorly understood. This study aimed to identify genes involved in gonadal sex differentiation and to investigate sexually dimorphic gene expression in undifferentiated gonads. RNA‐seq analyses using next‐generation sequencers were carried out on undifferentiated gonads of five 9‐month‐old juvenile Russian sturgeon Acipenser gueldenstaedtii. A total of 45 686 832 (8498 Mb) and 79 743 269 (7887 Mb) quality‐controlled reads were obtained using Ion PGM and HiSeq 2000 sequencers, respectively, and were assembled into 338 648 contigs (N50: 532 b). tBLASTx analyses identified 26 transcripts potentially involved in gonadal differentiation. Read‐mapping analyses were performed to obtain relative transcript levels (RPKM values). Multivariate analyses of the RPKM values of five transcripts (gsdf, dmrt1a, dmrt1b, foxl2 and cyp19a1a) showed that the five individuals could be separated into two distinct groups. One group, comprising two individuals, had increased levels of foxl2, hsd17b1 and cyp19a1a, suggesting differentiation into females. Alternatively, levels of gsdf were higher in the other three individuals, suggesting differentiation into males. We describe the levels of 26 transcripts potentially involved in gonadal differentiation in undifferentiated sturgeon gonads and suggest that levels of gsdf, foxl2, hsd17b1 and cyp19a1a are appropriate sexing markers for sturgeon at an early developmental stage.
      PubDate: 2014-08-30T03:33:37.137056-05:
      DOI: 10.1111/jai.12588
       
  • Induced spawning of wild‐caught adult lake sturgeon: assessment of
           hormonal and stress responses, gamete quality, and survival
    • Authors: J. Genz; C. A. McDougall, D. Burnett, L. Arcinas, S. Khetoo, W. G. Anderson
      First page: 1565
      Abstract: This research assessed the endocrine and physiological effects of Ovaprim™ and synthetic homologous sturgeon gonadotrophic releasing hormone (GnRH) on spawning male and female adult lake sturgeon, Acipenser fulvescens (Rafinesque, 1817). Wild‐caught adults were administered Ovaprim, GnRH, or Ringers solution (control), and serial blood samples were collected for up to 27 days following capture and hormone administration. Circulating cortisol levels appeared to increase following administration of both hormonal treatments. However, circulating cortisol was higher and plasma pH lower at capture than at any other time for all treatments, indicating that capture and transport stress were the largest disrupting factors, more so than the effects of induced spawning. Plasma concentrations of estradiol and testosterone in both sexes were similar to previously reported values. In all treatments the circulating estradiol and testosterone never significantly exceeded the values at capture prior to endocrine manipulation of the reproductive axis. Similarly, testosterone in males and estradiol in females in the muscle tissue were consistently at the same or lower concentrations than at capture. The apparent survival of all of the study animals following return to their native river indicated that the stress effects from capture and induced spawning were not severe. In concert, our results suggest that hormonal injections can be used to aid in gamete collection from wild A. fulvescens, without negative effects on long‐term broodstock survival. Hatching success, larval survival to the juvenile stage, egg diameter, and concentrations of protein, triglyceride, and glucose in the egg, sperm, and ovarian fluid (but not seminal plasma), were the same or greater in GnRH‐treated fish than gametes from the Ovaprim‐treated group, suggesting that utilization of GnRH may be preferable to other common methods of spawning induction.
      PubDate: 2014-08-23T02:29:26.035759-05:
      DOI: 10.1111/jai.12548
       
  • Use of sex steroid profiles and hematological indices to identify
           perinucleolus and migratory gonadal stages of captive Siberian sturgeon
           Acipenser baerii (Brandt, 1869) females
    • Authors: B. Falahatkar; S. R. Akhavan, S. Poursaeid, E. Hasirbaf
      First page: 1578
      Abstract: This study describes the sex steroid profiles and hematological indices of 5‐year‐old reared female Siberian sturgeon, Acipenser baerii, at perinucleolus and migratory stages to ascertain whether they are influenced by the maturity stage. Fish of 2923 g mean weight and 89 cm mean length were reared in rectangular concrete tanks (25 × 3 × 0.6 m, mean water temperature 16.2 ± 2.2°C, fed a diet with 38.2% crude protein and 7% crude fat in 10 kg m−2). Blood samples were taken for serum steroid levels, including 17‐β estradiol (E2), testosterone (T), 17α‐hydroxy progesterone (P) and hematological indices (packed cell volume, hemoglobin, red blood cells, white blood cells, mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration as well as leukocyte differential counts). Hematological indices and the leukocyte differential count showed no significant differences among fish at the perinucleolus and migratory stages. The results indicated significant differences in E2 levels among fish at the perinucleolus and migratory stage, but the T and P levels showed no significant differences between stages. This study indicates that serum sex steroid measurements and histological observations can segregate females effectively at the perinucleolus and migratory stages; however, the hematological parameters did not discriminate females at these stages. Such observations provide basic information to achieve a method to determine with high accuracy the stage of sexual maturity, for better sturgeon aquaculture management.
      PubDate: 2014-11-12T08:08:29.309913-05:
      DOI: 10.1111/jai.12616
       
  • Effect of cryopreservation on the enzyme activity of Russian sturgeon
           (Acipenser gueldenstaedtii Brandt & Ratzeburg, 1833) semen
    • Authors: X.‐R. Huang; P. Zhuang, L.‐Z. Zhang, J.‐Y. Liu, T. Zhang, G.‐P. Feng, F. Zhao
      First page: 1585
      Abstract: The hypothesis was tested that cryodamage occurs during the storage of semen at −196°C and that cryopreservation has a negative effect on the enzyme activity and motility of semen in the Russian sturgeon, Acipenser gueldenstaedtii. In addition, the aim of the study was to determine the activity of metabolic enzymes, including adenosintriphosphatase (total ATPase), creatine kinase (CK), succinate dehydrogenase (SDH) and lactate dehydrogenase (LDH), plus antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH‐Px) and glutathione reductase (GR). After cryopreservation (storage at −196°C), the motility and duration of semen fell and the total ATPase, SDH, LDH and CK activity in the spermatozoa was reduced. In the seminal plasma, however, total ATPase, SDH, LDH and CK activity increased markedly. Activity also notably increased in the group with no diluents or cryoprotectants. SOD, CAT and GSH‐Px activities also increased in the seminal plasma but dropped with regard to the spermatozoa, whereas the GR activity varied. The antioxidant enzyme activity trend between the groups with and without the addition of cryoprotectants was the same as in the metabolic enzyme activity. Cryopreservation had a great effect on the enzyme activity and motility of A. gueldenstaedtii semen; however, the cryoprotectant protected the semen during cryopreservation.
      PubDate: 2014-10-17T03:57:31.644969-05:
      DOI: 10.1111/jai.12608
       
  • Effects of delayed initial feeding on growth and survival of Chinese
           sturgeon (Acipenser sinensis Gray, 1835) larvae
    • Authors: Y. Chai; F. X. Tan, L. X. Li, Q. W. Wei
      First page: 1590
      Abstract: The goal of this study was to determine the point of no return (PNR) for Acipenser sinensis larvae and their growth in relation to delayed initial feeding. During the experiment at 23.2 ± 0.8°C, the initial feeding rates increased from 7.7 to 73.7% in larvae at age 7–12 dph (days post‐hatch). When delayed initial feeding was conducted at 14 dph, the initial feeding rate was as low as 37.3%. The rate declined even further thereafter, thus the PNR was assumed to have been reached by 14 dph. The survival rates were more than 80% at 7–2 dph, thereafter falling dramatically. Total lengths of larvae and body weights increased gradually and reached the maximum at 12 dph, then decreased and were even less than those at 7 dph. It was concluded that the optimal time for exogenous feeding was at 9–10 dph.
      PubDate: 2014-11-27T05:59:27.226631-05:
      DOI: 10.1111/jai.12626
       
  • Food preference of paddlefish, Polyodon spathula (Walbaum, 1792), in
           polyculture with bighead carp Aristichthys nobilis (Richardson, 1845) in
           non‐fed ponds
    • Authors: Y. J. Zhu; X. M. Li, D. G. Yang
      First page: 1596
      Abstract: The food preferences of paddlefish (Polyodon spathula) in polyculture with bighead carp (Aristichthys nobilis) are unknown. Three consecutive analyses of gastrointestinal contents of paddlefish and bighead carp were conducted at 3d, 11d and 19d after introduction into the non‐fed ponds. The objectives of this study were to test for competitive interactions between bighead carp and paddlefish, and to document their preferred prey when the two species have a limited food resource. The results showed that paddlefish and bighead carp are basically competitive in their diets. When they were cultured in one pond at the same density, paddlefish fed more quickly and efficiently, depleting the food resources for bighead carp; however, bighead carp were able to switch and trap small food items with the decrease in available food resources. Moreover, larger zooplankton abundance declined in ponds after fish were introduced.
      PubDate: 2014-09-11T00:59:27.684895-05:
      DOI: 10.1111/jai.12590
       
  • Effects of different dietary lipid sources on growth performance, tissue
           fatty acid composition and serum lipid indices of juvenile Amur sturgeon,
           Acipenser schrenckii Brandt, 1869
    • Authors: F. Huang; M. Jiang, H. Wen, W. Liu, C. G. Yang, F. Wu, J. Tian, Q.W. Wie
      First page: 1602
      Abstract: The present study was conducted to investigate the effects of different dietary lipid sources on the growth performance, tissue fatty acid composition and serum lipids indices of juvenile Acipenser schrenckii. Seven experimental diets were formulated with 10% lipid originating from fish oil (FO), sunflower oil (SFO), tallow oil (TO), pork lard (PL), rapeseed oil (RO), corn oil (CO) and soybean oil (SBO), respectively. Triplicate groups of 20 Amur sturgeon [initial body weight (9.83 ± 0.19) g; means ± SD] were cultured in 405‐L flow‐through aquaria and assigned to the experimental diets for 8 weeks. Results showed that fish fed the SBO diet had the highest weight gain rate (611.29%), significantly higher than that of fish fed the FO (539.14%), CO (540.56%) or SFO (451.27%, the lowest) diet (P 
      PubDate: 2014-09-24T04:03:09.990048-05:
      DOI: 10.1111/jai.12598
       
  • Effect of dietary carbohydrate sources on the growth performance, feed
           utilization, muscle composition, postprandial glycemic and glycogen
           response of Amur sturgeon, Acipenser schrenckii Brandt, 1869
    • Authors: M. Jiang; W. Liu, H. Wen, F. Huang, F. Wu, J. Tian, C. G. Yang, W. M. Wang, Q. W. Wei
      First page: 1613
      Abstract: The present study was conducted to compare growth performance, feed utilization, muscle composition, and postprandial glycemic and glycogen responses of juvenile Amur sturgeon, Acipenser schrenckii, fed different carbohydrate diets in order to select the most appropriate carbohydrate sources for this species. Six experimental diets were formulated containing 22% glucose, fructose, maltose, dextrin, α‐starch or cornstarch, respectively. Triplicate groups of 20 fish (average weight: (4.7 ± 0.1) g, means ± SD) were randomly fed one of the six diets for eight weeks. Results showed that the weight gain rate was highest in fish fed the dextrin (716.0%) or α‐starch diet (782.9%), and lowest in fish fed the fructose diet (333.2%). Specific growth rate and feed efficiency showed a similar weight gain rate pattern. Apparent digestibility of dietary carbohydrate for Amur sturgeon was the fructose, glucose> maltose> dextrin> α‐starch > cornstarch diet; apparent digestibility of dietary protein was the fructose> glucose, maltose, dextrin> cornstarch> α‐starch diet. Contents of muscle moisture, ash and crude lipid were significantly affected by the difference in dietary carbohydrate sources (P  0.05). Dietary carbohydrate sources significantly affected plasma glucose and liver glycogen concentrations in sturgeon in different periods after feeding (P 
      PubDate: 2014-09-22T02:27:29.652927-05:
      DOI: 10.1111/jai.12600
       
  • Influence of different levels of dietary choline on growth rate, body
           composition, Hematological indices and liver lipid of juvenile Siberian
           sturgeon Acipenser baerii Brandt, 1869
    • Authors: M. A. Yazdani Sadati; M. H. Sayed Hassani, M. Pourkazemi, M. Shakourian, M. Pourasadi
      First page: 1632
      Abstract: A 12‐week feeding trial was carried out to evaluate the effects of different levels of dietary choline on growth rate, body composition and total liver lipid of juvenile Siberian sturgeon, Acipenser baerii. A semi‐purified basal diet was formulated using vitamin‐free casein and wheat gluten as a protein source, a mixture of animal and plant oils as a lipid source, and dextrin as a carbohydrate source. Graded levels of choline chloride were used at 0, 2000, 4000, and 8000 mg kg−1 diet (actual choline concentrations: 0, 1500, 3500 and 7500 mg kg−1 diet) were added to the basal diet. Juvenile Acipenser baerii with initial mean weights of 37.67 ± 2.92 g were held in fiberglass tanks (500 l) and fed to apparent satiation three times per day. Weight gain, feed conversion ratio (FCR), specific growth rate (SGR) and protein efficiency ratio (PER) were significantly affected by dietary choline concentrations (P  0.05). The results of this study revealed that the optimum dietary choline chloride level for normal growth performance of juvenile Acipenser baerii appears to be 1500 mg kg−1.
      PubDate: 2014-11-27T05:59:25.787768-05:
      DOI: 10.1111/jai.12619
       
  • Dietary lipid to carbohydrate ratio in beluga, Huso huso (Linnaeus, 1758),
           fed two L‐carnitine levels
    • Authors: M. Mohseni; R. O. A. Ozório
      First page: 1637
      Abstract: A feeding experiment was carried out to determine the optimal dietary lipid: carbohydrate ratio (L:CHO, in %) on growth performance and feed efficiency in beluga, Huso huso (Linnaeus, 1758), juveniles fed two L‐carnitine supplementation levels. Triplicate groups (25 fish/tank) were fed one of eight isoproteic (41% crude protein) and isoenergetic (20 kJ kg−1 diet) diets with increasing L:CHO ratios (12 : 21, 15 : 16, 18 : 5 and 21 : 0) and one of two L‐carnitine supplements (0 or 300 mg kg−1). Fish (initial body weight 480 ± 18.4 g) were housed in 24 fiberglass tanks and fed to apparent satiation for 114 days. Fish fed the 18 : 5: and 21 : 0 had higher weight gain, growth rate, feed conversion ratio and protein efficiency ratio than fish fed the other diets. Growth performance was significantly improved by supplementing 300 mg L‐carnitine to diets. Liver lipid increased with increasing dietary L:CHO ratios and decreased with dietary L‐carnitine level. These results indicated that juvenile beluga did not utilize dietary carbohydrate as efficiently as lipid. Moreover, diets with a dietary lipid:CHO ratio between 18 : 5 and 21 : 0 and supplemented with 300 mg L‐carnitine kg−1 successfully improved growth performance and feed utilization of beluga sturgeon reared in intensive culture conditions.
      PubDate: 2014-09-10T23:11:20.567593-05:
      DOI: 10.1111/jai.12567
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-2014