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1.
拟穴青蟹幼蟹耗氧率和窒息点的研究 总被引：3，自引：1，他引：2
在盐度20、温度28.0±0.2℃条件下,采用密封流水方法进行了拟穴青蟹幼蟹耗氧率和窒息点的研究。结果表明:拟穴青蟹Ⅴ期幼蟹的平均耗氧率高于Ⅵ期幼蟹,Ⅴ期幼蟹的窒息点也高于Ⅵ期幼蟹。其中,当蟹苗体质量为1.00±0.22 g时,耗氧率为0.437 2±0.083 mg/(g.h),耗氧量0.423 7±0.080 mg/(ind.h),窒息点为0.716 0±0.017 mg/L;当蟹苗体质量为1.81±0.30 g时,耗氧率为0.381 6±0.081 mg/(g.h),耗氧量0.671 7±0.140 mg/(ind.h),窒息点为0.698 7±0.011 mg/L。实验发现,拟穴青蟹幼蟹的耗氧率和耗氧量具有比较明显的昼夜变化规律,其峰值出现在20∶00及02∶00左右,谷值出现在08∶00及16∶00。研究结果可为拟穴青蟹养殖生产中制定合理的苗种放养密度和养殖工艺提供参考依据。 相似文献
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盐度对中华绒螯蟹仔蟹标准代谢的影响 总被引：2，自引：1，他引：1
对均重(0.12±0.01)g的中华绒螯蟹(Eriocheir sinensis)仔蟹在6个盐度(0、4、8、12、16、20)梯度下的标准代谢进行研究。各梯度的水温为(24±0.5)℃、溶解氧为(8.12±0.23)g/m L、p H为7.5±0.18。在不同时间段测量各盐度梯度代谢瓶内溶氧量、CO_2含量及NH_3-N含量,将时间与耗氧率、CO_2排出率及NH_3-N排泄率进行回归分析。研究结果表明,根据仔蟹行为及代谢瓶内氧气含量与时间(h)的回归分析将仔蟹行为可分3个阶段:自由运动阶段[DO2.33 mg/L]、生存阶段[0.33 mg/LDO2.33 mg/L]及窒息阶段[DO0.33 mg/L]。在自由运动阶段和生存阶段,盐度对仔蟹耗氧率、CO_2排出率及NH_3-N排泄率影响显著(P0.05);在窒息阶段,盐度对仔蟹的耗氧率、CO_2排出率及NH_3-N排泄率影响不显著(P0.05)。研究结果还表明中华绒螯蟹仔蟹在高溶氧环境的主要供能物质为脂肪;低溶氧环境的主要供能物质为脂肪和碳水化合物;蛋白质在能量供给中的比例随溶氧增加而逐渐增加。 相似文献
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甲醛对合浦绒螯蟹的急性毒性研究 总被引：1，自引：0，他引：1
在水温24~30℃、溶解氧5mg/L及pH 8.5~8.8条件下,采用急性毒性试验方法,研究不同含量甲醛对质量约16g的合浦绒螯蟹的急性毒性。结果表明,48h以内,甲醛质量浓度低于500mg/L对合浦绒螯蟹的存活率和存活时间无显著影响(P0.05),96h以内,甲醛质量浓底低于250mg/L对合浦绒螯蟹的存活率和存活时间无显著影响(P0.05);甲醛对合浦绒螯蟹的12、24、36、48、60、72、84、96h半致死质量浓度分别为1991.788、1644.522、1273.757、1724.642、1177.963、1147.138、963.129、873.590mg/L,安全质量浓度为87.359mg/L。 相似文献
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胭脂鱼幼鱼的耗氧率及窒息点研究 总被引：1，自引：0，他引：1
在自制的可控温密封式流水呼吸室内,对0+龄胭脂鱼(Myxocyprinus asiaticus)的耗氧率和耗氧量进行了测定,并对0+龄和1+龄胭脂鱼的窒息点和窒息过程作了分析。结果显示,平均体重6~7 g的0+龄胭脂鱼在15℃时的平均耗氧率和耗氧量分别为0.0585 mg/(g.h)和0.3567 mg/(尾.h);20℃时的平均耗氧率和耗氧量为0.1176 mg/(g.h)和0.8232 mg/(尾.h);昼间耗氧率与夜间耗氧率未显差异。15、20、25和30℃下0+龄胭脂鱼的窒息点分别为0.4921、0.8319、0.9356和1.5144 mg/L,25和30℃下1+龄胭脂鱼的窒息点为1.0738和1.1027 mg/L。 相似文献
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在实验室内对2种规格宝石鲈的耗氧率、耗氧量及窒息点进行了测定。实验用水为曝气24 h以上的自来水,水温 25℃,pH值6.5-7．0,D04．9 mg/L。结果表明:宝石鲈的耗氧率随体重增加而降低,而耗氧量和窒息点随体重的增加而上升。平均体长4．77 cm、体重2．18g/尾的宝石鲈耗氧率为0．2561 mg/g·h,耗氧量0．5654 mg/尾·h,窒息点0．448 mg/L;平均体长6．09 cm、体重4．78 g/尾的宝石鲈耗氧率为0．2473 mg/g·h,耗氧量1．1840 mg/尾·h,窒息点0．632 mg/L。 相似文献
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暗纹东方Tun鱼苗耗氧率和窒息点的初步研究 总被引：1，自引：1，他引：1
对暗纹东方鱼屯两个规格鱼苗的耗氧量、耗氧率和窒息点进行了测定.结果显示在水温31～34℃,pH
6.5～6.8条件下,平均全长2.36 cm、体重0.429 g的鱼苗24 h平均耗氧量0.321
mg/(尾·h),耗氧率1.149 mg/(g·h),窒息点1.309 mg/L;平均全长3.49 cm、体重0.569
g的鱼苗24 h平均耗氧量0.837 mg/(尾·h),耗氧率0.968 mg/(g·h),窒息点1.486
mg/L. 相似文献
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为研究水稻种植过程中常用除草剂草甘膦对中华绒螯蟹幼蟹的毒性作用,通过48 h半静水法测定草甘膦对中华绒螯蟹的半致死浓度(LC50)和安全浓度(SC),并据此结果设定28 d慢性试验浓度,测定中华绒螯蟹的死亡率、蜕壳率和平均蜕壳天数,以及肝胰腺组织学变化。试验结果表明,急性毒性试验中,草甘膦12、24、36、48 h对中华绒螯蟹的半致死浓度分别为18.91、16.67、13.99、12.09 mg/L,安全浓度为1.9 mg/L;慢性毒性试验中,相比对照组,试验组草甘膦浓度达到0.6 mg/L后中华绒螯蟹的死亡率显著升高,草甘膦浓度达到0.3 mg/L时中华绒螯蟹的蜕壳率显著降低,各组间平均蜕壳时间统计学显示无明显差异,但组织学试验表明,中华绒螯蟹长时间暴露于低于安全浓度的草甘膦中依然会造成肝胰腺的损伤。 相似文献
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在水温 2 4 .4～ 2 6.0℃时对斑鱼种 (尾重 1.12～ 4 .61g )进行了耗氧率与窒息点测定。结果表明 :耗氧率与窒息点均随鱼体体重的增加而降低。平均尾重 4 .61g的斑耗氧率为0 .1580 mg/g.h ,窒息点为 0 .12 92 mg/L ;平均尾重 1.12 g的斑耗氧率为 0 .2 636mg/g.h ,窒息点为 0 .30 4 0 mg/L。白昼和夜晚耗氧率的差异不大 相似文献
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叶尔羌高原鳅耗氧率和窒息点的初步研究 总被引：1，自引：0，他引：1
试验采用流水呼吸室法和静水呼吸室法测定了叶尔羌高原鳅的耗氧率和窒息点。结果表明，叶尔羌高原鳅耗氧率具有昼夜节律性，白天（7：00-21：00）平均耗氧率为0．1389mg／（g·h），夜间（22：00-6：00）平均耗氧率为0．1799mg／（g·h）。其耗氧率和窒息点随体重的增加而降低，均体重为7．66g，耗氧率为0．1560mg／（g·h），窒息点为1．2105mg／L；均体重为20．30g，耗氧率为0．1201mg／（g·h），窒息点为1．1314mg／L；均体重为47．60g，耗氧率为0．0925mg／（g·h），窒息点为1．0937mg／L。其耗氧率和窒息点随水温的升高而增大，水温20℃，耗氧率为0．1260mg／（g·h），窒息点为1．1805mg／L；水温25℃，耗氧率为0．1603mg／（g·h），窒息点为1．3109mg／L；水温29℃，耗氧率为0．2231mg／（g·h），窒息点为1．5816mg／L。研究结果为养殖生产中合理放养、水质管理、饵料投喂和活鱼运输提供了依据。 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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