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本通过人工繁殖的月鳢苗种在池塘饲养至亲鱼，并进行亲鱼配对方式对比、饵料种类比较、孵化方式比较等试验，共配对亲鱼551对次，产卵总量51．4万粒，受精卵31．8万粒，孵出仔鱼27．3万尾，出苗20．2万尾(34∽52mm)：平均受精率61．84％，平均孵化率85．79％，平均出苗率74．14％。 相似文献
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乌苏里拟鲿苗种培育技术 总被引：1，自引：0，他引：1
选用经人工繁殖刚开口摄食的乌苏里拟鲿水花，在池塘和水族箱内同时进行培育。池塘每667m^2投放水花3万尾，水族箱内投放水花400尾。3个月培育结果表明，池塘养殖的乌苏里拟鲿体长由1．21cm增长至15．31cm，体重由0.023g／尾增重至28．25g／尾，成活率为96．8％；水族箱培育的乌苏里拟鲿体长增长至5．76cm，体重增长至1.92g／尾，成活率为33％。雌雄个体生长不均，池塘培育雌性个体平均体长为10．2cm，体重为16．5g／尾，雄性个体平均体长为21,8cm，体重为60Ag／尾；水族箱培育雌性个体平均体长为5．6cm，体重为1．49g／尾，雄性个体平均体长为6．6cm，体重为2．42g／尾。 相似文献
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在广西水产研究所那马中试基地进行了池塘养殖当年繁殖的奥尼罗非鱼苗种达出口规格试验。在1800m^2池塘中投放全长为3—4cm的奥尼罗非鱼鱼苗2860尾，经178d养殖，奥尼罗非鱼平均体重为O．75kg/尾(最大为1．1kg／尾)，平均体长为26．1cm(最大为29．5cm)，总产量为1750kg，平均产量为648kg／667m^2，养殖成活率为81．6％。 相似文献
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对131尾南方鲇鱼种(体长30mm—134mm)形态进行仔细观察，并量化分析。结果显示，南方鲇鱼种(1)口宽阔，口裂宽占头长48．5％—63．6％，平均为56．4％，吻长(口裂长)占头长的25．6％—42．8％平均为33．9％，又均不随鱼种生长而出现较大变化；(2)南方鲇的头长占体长的22．7％—30．8％之间，平均为24.6％，比例随着鱼种的生长而逐渐变小，体长达70mm以后，比例显著降低；(3)体高占体长的13．8％—24.1％，平均为16．4％。随着鱼种规格的增大而逐渐变大，体长达60mm后比例显著变大(4)尾鳍不对称，上叶明显长于下叶，上下叶长度之比为1．2—1．6，平均为1．33，随着鱼体生长无显著变化。 相似文献
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从湖北引进匙吻鲟鱼苗5万尾,平均体长1．9cm,平均体重0．028g,苗体健康无病。将鱼苗平均放人两口9m^2的水泥培育池内（放养密度约为2700尾/m^2）,利用池塘内的纯氧充气系统,采用枝角类为主的浮游动物为饵料培育至体长为7．0．8．00n后,采用人工配合饲料进行转饵驯化,经过50d的培育,鱼苗平均体长达到14．2cm,平均体重达18．01g,成活率为59．8％,取得了较好的培育效果。 相似文献
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北方地区内陆平原盐碱地兑水养殖东方对虾试验 总被引：7，自引：3，他引：7
利用面积为2000m^2的盐碱地池塘，以地下机井卤水为主要水源，通过向卤水内补充kcl和添加内陆鱼池淡水作为养殖用水进行东方对虾（Penaeus chinensis)养殖。投放体长0．8cm仔虾8万尾，40尾/m^2，养殖160d,至起捕时共产对虾517．5kg，平均体长14．1cm，纯收益36690元，平均收益为18．35元／m^2，饵料系数1．88。 相似文献
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南美白对虾高位池生态育苗试验 总被引：1，自引：0，他引：1
2005年5月在湛江东海岛,利用养虾高位池3个,总面积4000m^2,共投放无节幼体4．2亿尾,培育南美白对虾仔虾（PL2-PL3）2761万尾,平均成活率6．6％,平均单产6574尾／m^2。 相似文献
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Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean 
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下载免费PDF全文 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. 相似文献
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Liping Li Rui Wang Wanwen Liang Xi Gan Ting Huang Yan Huang Jian Li Yunliang Shi Honglin Luo Ming Chen 《广西水产科技》2014,(1)
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. 相似文献
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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. 相似文献
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Iciar Martinez Amaya Velasco Ricardo Pérez-Martín Eskil Forås Michiaki Yamashita Carmen G. Sotelo 《Journal Of Aquatic Food Product Technology》2013,22(4):289-297
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. 相似文献
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Growth hormone (GH) and reproduction: a review 总被引：5，自引：0，他引：5
Florence Le Gac Odile Blaise Alex Fostier Pierre-Yves Le Bail Maurice Loir Brigitte Mourot Claudine Weil 《Fish physiology and biochemistry》1993,11(1-6):219-232
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. 相似文献
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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. 相似文献
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Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection 下载免费PDF全文
下载免费PDF全文 G Sharon M Pimenta‐Leibowitz M C L Vilchis N Isakov D Zilberg 《Journal of fish diseases》2015,38(1):67-74
Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality). 相似文献
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