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消化酶活性是反映鱼类消化生理机能的一项重要指标,鱼类消化酶活性的高低决定鱼类对营养物质消化吸收的能力,从而决定鱼类生长发育的速度。国内外对鱼类消化酶进行了广泛研究,随着消化酶研究领域的深入,饲料与消化酶的关系也开始探讨。饲料对美国红鱼蛋白酶活性研究尚未见报道,本文对饲料与美国红鱼幼鱼蛋白酶活性的关系开展研究,以期为美国红鱼人工配合饲料的研究和养殖提供有价值的参考资料。 相似文献
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pH影响暗纹东方鲀蛋白酶活性的研究 总被引：4，自引：2，他引：2
鱼类消化酶的研究是鱼类消化生理的重要研究内容 ,也为配合饲料的研制提供依据 ,暗纹东方鱼屯 ,俗称河豚 ,是我国特有种类。随着人繁技术的成功 ,暗纹东方鱼屯也成了具有极高经济价值的特种水产养殖对象 ,因此对其消化酶的研究具有重要意义 ,消化酶活性与环境因素有密切关系 ,其中ｐＨ是主要影响因素。本文报道ｐＨ影响暗纹东方鱼屯蛋白酶活性的初步研究成果 ,期望对配合饲料的研制有所帮助。1 材料与方法1 1 材料来源与酶液制备实验鱼来自我院特种水产养殖基地 ,鱼苗为1999年春季人工繁殖的 ,淡水养殖 ,均健康无伤。全长范围 12 0～ 1… 相似文献
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复合酶制剂对鲤鱼消化酶活性的影响 总被引：9，自引：0，他引：9
鱼类消化酶的研究既是消化生理的重要内容，也是设计饵料配方的依据。鲤鱼作为我国主养鱼类之一，其消化酶的研究无疑具有重要意义。为此，笔者用添加复合酶制剂的饲料饲养鲤鱼一段时间，对其肠道、肝胰脏的蛋白酶、淀粉酶活性进行了初步研究，旨在探讨复合酶制剂对消化酶活性的影响。一、材料与方法１．实验用鱼实验用鲤鱼购于静海团泊洼，购回后在实验室条件下（１８℃～２５℃）于水族箱（其规格为６５cm×３８cm×４５cm中暂养２d，每尾鲤鱼的体重在（２４．８±９．５５）g～（２９．８±８．９９）g，体长在（９．８±１．４７）cm～… 相似文献
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为研究池塘多元养殖模式下不同饲料投喂模式对脊尾白虾（）生长、消化酶活性、体成分及养殖水环境的影响，实验以脊尾白虾及其养殖水为研究对象，设置3个实验组，分别为投喂冰鲜饲料组（Diet1组）、投喂配合饲料组（Diet3组）及两者1：1混合投喂组（Diet2组）。每个实验组设3个重复，实验周期为45 d，实验每隔5 d测脊尾白虾体重和养殖水质指标并分析；实验结束时，采集脊尾白虾样品，用于消化酶及体成分的测定与分析。结果显示：（1）不同饲料投喂30 d后，Diet2组脊尾白虾的体重显著高于Diet1组和Diet3组（>0.05）；增重率与特定生长率随时间呈下降趋势。（2）从Diet1组至Diet3组饲料中蛋白水平逐渐降低，而脊尾白虾蛋白酶活性逐渐降低，淀粉酶活性逐渐提高；各实验组脂肪酶活性差异不显著（P>0.05）。Diet2组脊尾白虾水分含量显著低于Diet1组和Diet3组（>0.05）。（4）随着实验的进行，脊尾白虾养殖水环境中COD、氨氮、亚硝酸盐、硝酸盐、无机氮及无机磷均呈上升趋势，实验结束时，各水质指标由高到低依次为Diet1组、Diet2组、Diet3组。因此，池塘多元养殖模式下混合投喂"冰鲜饲料+人工配合饲料"，有利于脊尾白虾的生长、消化及蛋白积累，然而对养殖水环境仍存在一定的污染，研制环保型人工配合饲料仍是大势所趋。 相似文献
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菊黄东方鲀当年鱼种养殖阶段消化酶活性研究 总被引：2，自引：0，他引：2
为了研究池塘养殖菊黄东方鲀（Takifugu flavidus）鱼种生长及肠组织中消化酶活性随生长的变化,2012年5－11月进行室外养殖试验,池塘面积0.2 hm2,水深1.5～2.0 m,鱼苗体长1.2~1.5 cm,放养密度为22.5 万尾/hm2,试验用海水盐度5~15,水温为15~35℃,pH 8~9;测定当年鱼种不同生长阶段的体长、体质量、肝重、肠长等生长指标,通过生物化学方法测定了其肠组织主要消化酶活性。结果表明,菊黄东方鲀幼鱼体长、体质量与养殖天数均呈指数相关（L=27.07e0.0088t, W=1.0982e0.0262t）;体长与体质量呈幂函数增长相关（W=3×10-5L3.1070）,且为异速生长。不同生长阶段菊黄东方鲀肝体比、比肠长、肥满度的变化显著（P<0.05）;肝体比随生长呈显著上升趋势（P<0.05）,变化范围为4.15%~20.23%;比肠长则呈显著下降趋势（P<0.05）,变化范围为0.97%～2.33%,不同生长阶段肥满度变化为3.99%～5.11%。菊黄东方鲀肠组织碱性蛋白酶和淀粉酶活性均随生长呈显著降低趋势（P<0.05）,最大值均出现在养殖40 d（83.11 U/mg与3.13 U/mg）;酸性蛋白酶活性呈先下降、后上升趋势（P<0.05）,最小值（0.34 U/mg）与最大值（0.86 U/mg）分别出现在113 d和166 d;脂肪酶活性随生长变化不显著（P>0.05）。研究表明,菊黄东方鲀鱼种的生长与养殖条件的改变存在密切关系;肝体比、比肠长等与鱼的发育及营养摄入存在一定关系;肠组织不是生成蛋白酶和淀粉酶的主要器官。 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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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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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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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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