共查询到20条相似文献，搜索用时 146 毫秒
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斑点叉尾鱼回是美国水产养殖的优良品种，我省开展其小体积高密度网箱养殖始于１９９５年，１９９７年进行了较大面积试验推广。我们在山仔水库使用小网箱５０只，在２００ｍ３水体中投放鱼种５５９９７尾，尾均重１４３ｇ，平均每箱放养１１２０尾。经过７个月的养殖，... 相似文献
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微型网箱养殖黄鳝技术研究 总被引：4，自引：1，他引：4
利用４只微型网箱及附设的人工寄居巢、食台、遮蔽物等属具，以每ｍ２放养尾均重１６．６ｇ、２０．８ｇ的黄鳝种３．２５～７．２７ｋｇ，通过药饵驱虫、投喂螺、蚯蚓浆配合饲料，观测并及时用光合细菌等调节水质及防治鳝病等技术措施，经９７和１２６ｄ的养殖试验研究，每ｍ２网箱平均毛产尾均重５６．９ｇ的黄鳝１４．５１ｋｇ，净产９．４９ｋｇ，成活率９１．９％，生长指标９．４２６８。研究初步说明网箱养鳝模式简便易行，每ｍ２放养尾均重２０ｇ．左右的鳝种４．０～４．７ｋｇ效果较好。 相似文献
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为了提高鱼池斑点叉尾Ｈｕｉ的养殖产量，作者在０．０４ｈａ的土质鱼池中，通过使成离心泵（２２７升／分）将底部池水陆列表层的方式，做了３次再循环水养殖研究，其中有２次研究抽取的池水通过１０００升的生物过滤器进行了处理。放养鱼种平均规格４５ｇ／尾，放养密度７４１０尾／ｈａ至１９７６０尾／ｈａ到１０６０１ｋｇ／ｈａ，商品鱼规格４５０ｇ以上，其中研究３中的一口鱼池产量最高为１３３８７ｋｇ／ｈａ。研究表明，再 相似文献
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１９９９年７月从北京引进俄罗斯鲟鱼苗种在广西水产学校名特优水产实验场（武鸣基地）进行了南移人工养殖实验，在室外水泥池中投放鲟鱼苗４５００尾，平均体长为７ｃｍ（５～１０ｃｍ），经１５３ｄ饲养，得鲟鱼种３１５０尾，平均体长为３７．８ｃｍ，均重２１５ｇ。其中最大个体体长为５０ｃｍ，体重３７８ｇ，养殖成活率为７０％。 相似文献
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南方大口鲶肉质细嫩，味道鲜美，养殖周期短，养殖利润是常规品种的３～６倍，深受养殖户和消费者喜爱。但是，一些缺乏经验的养殖户，由于种种原因，购进的南方大口鲶苗种成活率普遍偏低，使得部分养殖户遭受损失。笔者根据这几年的实践，将有关技术措施总结如下：１谨慎选购 一种是杂交型的大口鲶，其母本（属近亲繁殖）体重 ２． ５ ｋｇ左右，父本（土鲶、小口鲶）为本地鲶，体重 ３００～５００ ｇ，养殖 ２００天后，尾重在 ５００ ｇ以上。一种是本地鲶，父、母本纯属本地鲶，亲本体重２００～５００ ｇ，苗种养殖 ２００天后，尾重… 相似文献
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在３口０．８３亩池塘进行主养淡水白鲳的密度试验，分别放养平均尾重１４５ｇ鱼种５６０尾、９４０尾、７２５尾、并混养鲢、鳙、鲤、罗非鱼。结果：３口池塘分别折合每亩净产１２０６．２８ｋｇ，１３９２．０６ｋｇ，１０４３．４１ｋｇ，每亩纯收入６０００元左右。在盐度为１０的池塘中，养殖淡水白鲳，平均日增重６．７ｇ。 相似文献
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网箱养殖高背鲫及异育银鲫，投喂颗粒饲料。高背鲫单产１８４６ｋｇ／ｍ２，规格１６２ｇ／尾，增重倍数３０８；异育银鲫大网箱单产２０６８—２２３６ｋｇ／ｍ２，规格１７８—１８１５ｇ／尾，增重倍数３１３—３４５；异育银鲫小网箱单产１０８—１６７ｋｇ／ｍ２，规格１７２—１８６ｇ／尾，增重倍数３３４—４３２。 相似文献
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平均放养密度为３ｋｇ／ｍ２（尾重２１ｇ，全长３０ｃｍ），顺水泥池内以泥垅打洞作寄身巢的黄鳝，经９６ｄ的人工强化养殖，其生长比速为０．９６４４，生长指标为２８．９；平均增重率２７４．９％，平均每尾净增重５７．７ｇ，单产８．８ｋｇ／ｍ２。该结果初步表明，水泥池中强化养殖的黄鳝，生长速度远快于规格相近、在自然水域中生长的黄鳝． 相似文献
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斑点叉尾鮰实用养殖技术（六）──鱼病防治斑点叉尾鮰的鱼病防治是养殖过程中的一个重要环节，尤其在高密度养殖中显得突出，必须坚持“无病先防、有病早治、防重于治”的方针，切实落实好防病治病的措施。一、病毒性疾病病原：斑点叉尾病毒（ＣＣＶＤ）病状：病鱼皮肤及... 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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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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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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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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