小型水库养鱼技术开发试验

对１０３座小型水库养高产技术进行了开发试验，１９９１年试验１０８５７亩，总产鱼１９０９．８Ｔ，平均亩产１７５．９ｋｇ每亩勇利３３５．４元，１ｋｇ盈利１．９１元；投入产出比１：２．０８。专家鉴定认为，本试验的面积产量均达到国内先进水平。     

小型水库群养鱼高产技术研究

对小型水库的养鱼模式，网箱配置，水库施肥等高产技术进行了综合研究。１９９２年，试验水库４１座，面积３５１公顷，总产成鱼１２８３．６ｔ，平均每公顷产３６５７ｋｇ，净产３３１０．５ｋｇ，比开发前提高４．２７倍；每公顷纯利８８０４．２５元，投入产出比１：１．９２。１９９３年６月专家鉴定认为，本研究居国内同类技术开发的领先水平。     

许家崖大型水库增养殖技术开发

许家崖水库有可养鱼水面９００ｈｍ２．１９９４年采取了大水面养鱼．网箱养鱼．引进太湖银鱼，拦库汊养鱼等多方位技术开发．共产成鱼４９．９６万ｋｇ．其中大水面产鱼１６万ｋｇ．鲢、鳙鱼箱１２７３只．产鱼１９．３５万吨．网箱养鲤鱼、罗非鱼５４只．产鱼８．１１万ｋｇ．坝拦库汊两处１１．６７ｈｍ２．产鱼３．５万ｋｇ．产大银鱼３万ｋｇ．总产值５５３万元．纯利润３９９．８７１元．投入产出比１：３．６１。     

池塘养鱼中产变高产技术开发

４１７．２ｈｍ＾２池塘，总产成鱼１９８．０７万ｋｇ，新增产８７．６５万ｋｇ，增产幅度７９．３％，新增产值４３８．２５万元，新增利税２２３．５１万元，每６６７ｍ＾２平均产鱼３７６．７ｋｇ，获利９５８．５元，为开发前３年平均产量的１．７９倍。     

观上水库股份联营网箱养鲤试验

采取股份联营形式，每股５０００元，共集资２８万元，网箱养鲤４２５ｍ＾２，总产鱼３．８０５万ｋｇ，单产８９．５ｋｇ／ｍ＾２，饵料系数２．３。总收入３８．０５万元，获利税１１．１０２万元，投入产出比１：１．４，每股可分红１７２７元。     

配合颗粒饲料养鱼技术推广试验

１９９３～１９９４年，进行了８９－Ｘ配合颗粒饵料养鱼技术推广试验，并对配合颗粒饵料的原料选取、加工工艺及综合养鱼技术等进行了探讨。试验池塘５４７０亩，平均每亩产鱼８６８ｋｇ，纯益２６０４元，分别比试验前提高４５．６％、６４．８％；网箱养鱼１７．４亩，平均每亩产罗非鱼５５．Ｉｔ，纯益１２·８９万元，分别比试验前提高３７．８％、４８．１％。专家鉴定认为，本成果达到国内先进水平。     

水库三种养鱼方式效益比较试验研究

在水库中开展网箱带大库养鱼，投草养鱼和施化肥养鱼试验，并进行效益对比分析，参试水库１８座，面积２９０．２ｈａ。大库单产成鱼９８７ｋｇ／ｈａ，盈利１．６６元／ｋｇ，投入产出比为１：１．７４。对比结果表明：投入产出比和千克鱼盈利以网箱带大库养鱼方式最佳，单位面积的产量、产值，盈利，施化肥养鱼和投草养鱼指标基本接近，网箱带大库养鱼次之。     

温流水高产高效养鱼研究

利用电厂的余热水在７２９ｍ＾２的圆形流水池中主养罗非鱼１２０天，净产３６６７３．８ｋｇ，增重倍数３．０。饵料系数１．５３。折合年亩产１００．６ｔ。１ｍ＾２产鱼１５０．９ｋｇ，效益３４３０元，专家鉴定认为，本技术、单产、经济效益及管理水平均居国内领先水平。     

丘陵山区大面积积冬闲田养鱼技术

选择４０６．７８ｈｍ＾２稻田，从１１月上旬至次年４月下旬进行鱼种养殖，增产比例为１：３．０３。投入产出比为１：２．３９，每６６７ｍ＾２稻田产鱼８５．７ｋｇ，获纯收入民８．６９元。     

山塘小水库养鱼综合增产技术

1989-1991年在2．6万多亩山塘小水库开展养鱼综合增产技术试验。采取加强技术培训，推广先进实用养鱼技术等一系列措施，鱼产量连年大幅度增产增收。1989年5436亩山塘小水库平均亩产鱼62．8kg，亩产值352．8元，亩绀收199．2元；1990年10175亩山塘小水库平均亩产鱼76．8kg，亩产值436元，亩纯收306．6元；1991年．10.413亩山塘小水库平均亩产鱼96．9kg，亩产值540．3元，亩纯收395．8元。     

Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean

The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna.     

Rare serotype occurrence and PFGE genotypic diversity of Streptococcus agalactiae isolated from tilapia in China

Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China.     

Evaluation of a Fast Method Based on the Presence of Two Restriction Sites in the Mitochondrial ND5 (mt ND5) Gene for the Identification of Scomber Species

The purpose of this work was to evaluate the suitability of a method based on the presence of two restriction sites (for Hae III and Hindf I) in the mitochondrial NADH dehydrogenase subunit 5 (mt ND5) gene to identify Scomber species. The evaluation was performed on 144 reference and market samples by sequencing of the entire 505-bp fragment of the mt ND5 gene and of a 464-bp fragment of the Kocher fragment of the cytochrome b gene (mt Cytb). Sequence analysis of any of the two fragments allows the identification of each of the four Scomber species, but S. japonicus and S. colias had the same restriction sites at the ND5 amplicon and would not have been differentiated by this analysis. Similarly, loss of the Hae III site in some S. scombrus individuals would have misidentified them as not being Scomber. All the market products were correctly labeled except one acquired in Spain labeled as originating in the Atlantic and containing S. japonicus.     

Growth performance,digestive enzyme activity and immune response of Japanese sea bass,Lateolabrax japonicus fed with fructooligosaccharide

In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg.     

Growth hormone (GH) and reproduction: a review

Interaction between growth and reproduction occurs in many vertebrates and is particularly obvious at certain stages of the life cycle in fish. Endocrine interactions between the gonadotropic axis and the somatotropic axis are described, the potential role of GH being emphasised. A comparative analysis of these phenomena in mammals, amphibians and fish, suggests a specific role of GH in the physiology of puberty, gametogenesis and fertility. It also shows the original contribution made by studies on the fish model in this field of investigations.     

Purification and partial characterization of GtHs (cfLH and cfFSH) from Indian walking catfish (Clarias batrachus) (L.) and development of a homologous ELISA for cfLH

Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL^?1 (1.25 ng well^?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation.     

The optimal dietary protein level of juvenile silver sillago Sillago sihama at three dietary lipid levels

A 5 × 3 factorial growth trial was conducted to evaluate optimal dietary protein and lipid levels (dietary protein level, DP; dietary lipid level, DL) for juvenile Sillago sihama (S. sihama) (2.0 ± 0.02 g, initial weight). Fish were fed 15 diets containing 5 DPs (350, 400, 450, 500 and 550 g/kg) and 3 DLs (60, 90 and 120 g/kg) for 8 weeks. The interaction between proteins and lipids significantly influenced the feed conversion ratio, condition factor, body composition, antioxidant indices and lipase activity (p < .05). DP 450 g/kg showed the highest average final body weight. DPs 500 and 550 g/kg significantly decreased the protein efficiency ratio (p < .05). DL 120 g/kg showed the highest percentage weight gain. The low feed conversion ratio was found in diets P45L12, P55L9 and P55L12. Diet P45L12 showed high superoxide dismutase activities. DP 450 g/kg showed the lowest average malondialdehyde content. Lipase activity was increased by increasing DP (p < .05) with a fall at DP 550 g/kg. Under the present experimental conditions, the optimal DP for S. sihama was 450 g/kg under the DL 120 g/kg.