鱼体内致病菌种类、致病原因及控制对策

一、鱼体内条件致病菌种类 鱼类细菌性疾病是造成水产业严重损失的重要疾病,为此倍受国内外学者的关注。多项调查结果表明,危害我国水产养殖业的大多数病原菌为条件致病菌。这类细菌可长期潜伏在鱼体内并不引起疾病,但当环境突变或受污染、鱼体抵抗力下降时则可迅速导致疾病发生或     

鱼体内致病菌种类,致病原因及控制对策

１鱼体内条件致病菌种类鱼类细菌性疾病是造成水产业严重损失的重要疾病 ,为此倍受国内外学者的关注。多项调查结果表明 ,危害我国水产养殖业的大多数病原菌为条件致病菌。这类细菌可长期潜伏在鱼体内并不引起疾病 ,但当环境突变或受污染、鱼体抵抗力下降时则可迅速导致疾病发生或流行。据有关调查 ,正常鱼体内条件致病菌经初步鉴定 ,它们归属于８个菌属 ,其中气单胞菌属占５９．１%、不动杆菌占１３．３ %、黄杆菌占１０．８ %、肠球菌占１．２ %、克雷伯氏菌占１．２ %。它们在一定条件下引起鱼、鳖细菌性疾病的实例均有报道。而嗜水气单…     

鱼诺卡氏菌培养条件及培养基的优化

对鱼诺卡氏菌(Nocardia seriolea)ZJ0503的增菌培养基和生长条件进行优化。研究了温度、盐度、初始pH对鱼诺卡氏菌生长的影响,并通过单因素试验对培养基的碳源、氮源和无机盐成分进行了筛选,采用正交试验法对培养基各主要成分的添加量进行了优化。结果表明,鱼诺卡氏菌最适宜生长条件为温度25℃、盐度5、pH 6.5±0.2;经筛选,鱼诺卡氏菌培养基中最佳碳源是葡萄糖,最佳氮源是酵母粉,促生长作用最强的2种无机盐是磷酸氢二钾(K2HPO4)和氯化钙(CaCl2);确立了培养基优化配方为葡萄糖20 g·L-1,酵母粉15 g·L-1,K2HPO40.75 g·L-1,CaCl20.2 g·L-1(单独灭菌),氯化钠(NaCl)5 g·L-1,pH 6.5±0.2。     

鰤鱼诺卡氏菌培养条件及培养基的优化

对鰤鱼诺卡氏菌（Nocardia seriolea）ZJ0503的增菌培养基和生长条件进行优化。研究了温度、盐度、初始pH对鰤鱼诺卡氏菌生长的影响,并通过单因素试验对培养基的碳源、氮源和无机盐成分进行了筛选,采用正交实验法对培养基各主要成分的添加量进行了优化。结果表明,鰤鱼诺卡氏菌最适宜生长条件为温度25 ℃、盐度5、pH 6.5±0.2;经筛选,鰤鱼诺卡氏菌培养基中最佳碳源是葡萄糖,最佳氮源是酵母粉,促生长作用最强的2种无机盐是磷酸氢二钾（K2HPO4）和氯化钙（CaCl2）;确立了培养基优化配方为葡萄糖20 g·L-1,酵母粉15 g·L-1,K2HPO4 0.75 g·L-1,CaCl 20.2 g·L-1（单独灭菌）,氯化钠（NaCl2）5 g·L-1,pH 6.5±0.2。     

鱼的条件致病菌种类、致病原因及控制对策

随着水产养殖业的不断发展,养殖规模的不断扩大,集约化程度的不断提高,以及管理与技术措施滞后等诸多原因,水产动物病害已呈暴发趋势。据初步统计,目前我国人工养殖的鱼、虾、蟹、鳖、蛙等水产动物的病害就有２００种以上,每年因病害所造成的产量损失达 １５％～ ３０％,直接经济损失达数十亿,并有继续加重的趋势。 面对如此严峻的形势,如果我们仍象以往那样,采取“头疼医头,脚疼医脚”的方式,就会造成“按下葫芦,起来瓢”的十分被动的局面,无法取得防治的主动权。为此,我们必须对引起暴发性流行病的条件、致病菌的种类、致…     

三峡水库正常运行期间四大家鱼的时空分布特征

调查三峡水库正常运行期(2011-2015年)库区干流5个江段(秭归、巫山、云阳、涪陵、江津)的鱼类资源,对库区干流四大家鱼的时空分布特征进行研究,并探讨三峡库区四大家鱼受上游水电开发以及库区其他因素影响的情况,旨在为三峡库区四大家鱼保护措施的提出提供基础数据支撑。研究结果表明:四大家鱼在渔获物中的数量百分比从2011年的3.52%下降到2015年的1.86%,而重量百分比则先从2011年的13.47%迅速上升到2012年的28.06%,然后波动下降到2015年的24.30%,其中鲢、鳙、草鱼均在数量百分比上呈现波动下降趋势,而在重量百分比上则均呈现先上升后下降的趋势;5年间,四大家鱼的主要分布区域逐渐从涪陵至秭归江段转移到云阳和秭归江段,其中鲢、鳙、草鱼的主要分布区域均从云阳至秭归江段转移到云阳和秭归江段。三峡库区四大家鱼群体面临的主要问题是金沙江梯级水电站运行对其产卵活动的影响以及库区普遍的过度捕捞。     

养殖条件下鲻鱼生长发育的初步研究

鲻鱼（Mugil cophalus Linnaeus）是鲻科鱼类中分布最广且最早被人类利用及研究的对象之一，其个体大、生长快、抗病性强、食物链级次低，可在淡水、半咸水及海水中正常生长。有关鲻鱼生长发育的研究，国内外学者已做了不少工作。鲻鱼的生长情况与鲻鱼养殖的经济效益有着直接的关系，同时也影响到鲻鱼性腺的发育，关系到鲻鱼人工繁殖工作的研究。     

鱼体内APUD细胞的初步研究

本文对鱼体部分器官内APUD细胞的存在和分布,进行了初步探讨.     

黄、东海越冬鳀鱼的分布与水文条件的关系

越冬鳀鱼密集区主要分布于最适水温(11～13℃)水平梯度大的冷水或暖水舌锋区,其水平位置,范围大小和鱼群密集程度随最适水温分布趋势的逐月变化和年际变化而发生变化。 鳀鱼垂直分布有昼夜变化。在无温、盐跃层水域,白天鳀鱼分布于中下层或近底层,且易集成小群;夜间鱼群分散,几乎分布于整个水层。但在有温、盐跃层的水域,因受跃层的影响,鳀鱼常常分布于跃层之上的水层。     

6种中草药对4种淡水鱼致病菌体外抑菌作用的研究

研究了6种中草药对4种淡水鱼致病菌温和气单胞菌（Aerom onas sobria）、嗜水气单胞菌（A.hydrophila）、生物Ⅰ-荧光假单胞菌（Pseudom onas fluorescentb iotypeⅠ）和柱状黄杆菌（Flavobacterium columnaris）的体外抑菌作用。以黄连（Coptis chinensis）、大黄（Rhem officinale）、连翘（Forsythia suspensa）、鱼腥草（Houttuynia corda-ta）、厚朴（Magnolia officinalis）和大青叶（Folium isatidis）6种中草药的水提物为研究对象,采用滤纸片法检测其对4种致病菌的抑制活性,并分别测定了这6种植物提取物对供试菌的最小抑菌浓度（M IC）。结果表明,黄连水提物对4种淡水鱼致病菌的抑菌效果最好,大黄和连翘水提物次之,而鱼腥草、厚朴和大青叶水提物的抑菌效果不明显。     

淡水鱼类暴发性流行病的探讨

本文对该病的病原、流行情况、发病原因、症状分别进行分析，并通过分析提出合理的预防和治疗措施。     

Effective monitoring of freshwater fish

Freshwater ecosystems constitute only a small fraction of the planet's water resources, yet support much of its diversity, with freshwater fish accounting for more species than birds, mammals, amphibians or reptiles. Fresh waters are, however, particularly vulnerable to anthropogenic impacts, including habitat loss, climate and land use change, pollution and biological invasions. This environmental degradation, combined with unprecedented rates of biodiversity change, highlights the importance of robust and replicable programmes to monitor freshwater fish. Such monitoring programmes can have diverse aims, including confirming the presence of a single species (e.g., early detection of alien species), tracking changes in the abundance of threatened species, or documenting long‐term temporal changes in entire communities. Irrespective of their motivation, monitoring programmes are only fit for purpose if they have clearly articulated aims and collect data that can meet those aims. This review, therefore, highlights the importance of identifying the key aims in monitoring programmes and outlines the different methods of sampling freshwater fish that can be used to meet these aims. We emphasize that investigators must address issues around sampling design, statistical power, species’ detectability, taxonomy and ethics in their monitoring programmes. Additionally, programmes must ensure that high‐quality monitoring data are properly curated and deposited in repositories that will endure. Through fostering improved practice in freshwater fish monitoring, this review aims to help programmes improve understanding of the processes that shape the Earth's freshwater ecosystems and help protect these systems in face of rapid environmental change.     

淡水鱼产品保鲜技术研究现状

淡水鱼产品中不饱和脂肪酸含量较高,比畜肉和禽肉更容易被氧化,且鱼体细菌繁多,容易引起鱼肉蛋白的腐烂变质,因此淡水鱼产品的防腐保鲜一直是食品行业内的热点研究课题。本文主要介绍目前国内外普遍采用的淡水鱼产品保鲜技术,主要包括低温保鲜技术、包装保鲜技术、辐射杀菌保鲜技术、涂膜保鲜技术以及化学方法保鲜技术。     

On size and growth in freshwater fish

Patterns of growth and size achieved in freshwater fish are examined with relation to the issues of indeterminate and determinate growth and asymptotic growth. Various authors suggest minimum, average and maximum sizes attained by fish, variously pointing to very small gobies and very large sharks, with most fish being about 150 mm long. Growth in fish is distinctive in that typically it continues throughout life, even though it becomes slower with increasing age and the onset of sexual maturity. Growth rates and size achieved by fish are highly flexible and subject to both genetic and environmental controls, so that size reached may vary with environmental variables such as water temperatures and food availability (both food abundance and prey types and sizes). Frequency distributions of 5 disparate freshwater fish faunas (Papua-New Guinea 267 species and tropical; North America 709 species and subtropical to Arctic; Australia 176 species and tropical to temperate; New Zealand and Great Britain 27 and 39 species and both warm to cool temperate) closely resemble distributions generated by the theoretical model of Hutchinson & MacArthur, and also data on diverse faunas. Frequency distributions in these faunas are closely similar, with a majority of species being small. This similarity would seem to suggest a general explanation. However, examination of the freshwater fish fauna of North America suggests that, rather than showing a predominance of large fish in the Arctic, the fauna has more large fish towards the tropics, though the proportion of large fish there is lower owing to the proliferation of small species in the tropics and a paucity of them towards the Arctic. Analysis shows a shift in the size composition of the fauna with latitude and shows that the general pattern for the whole of North America consists of a composite series of rather different patterns. This suggests that there is probably no meaningful general explanation of the overall patterns seen in these diverse and disparate faunas and that the similarity in overall size distributions between freshwater fish faunas of North America, New Guinea, Australia and New Zealand are of little ecological or evolutionary significance. The generality of Cope's rule is questionable, especially for fish, in which dwarfing and/or evolution towards smaller size are seen to be common phenomena.     

淡水鱼类血清转铁蛋自遗传多态性研究

淡水鱼类血清转铁蛋自遗传多态性研究龙华，汤伏生，曾勇，王朝元（淡水鱼类种质资源与生物技术实验室，荆沙市４３４０００）关键词淡水鱼类，转铁蛋白，多态性，耐低氧ＳＴＵＤＩＥＳＯＮＧＥＮＥＴＩＣＰＯＬＹＭＯＲＰＨＩＳＭＳＯＦＦＲＥＳＨＷＡＴＥＲＦＩＳＨＳＥ...     

杜仲大蒜制剂对鱼类常见病原菌的抑菌作用

采用试管法测定杜仲提取物、大蒜素及其按不同比例配成复方制剂,通过对鱼类3种常见病原菌的体外抑菌、杀菌效果检测,探索杜仲提取物、大蒜素的抑菌性能,以及复方制剂的协同抑菌作用。结果表明:杜仲提取物、大蒜素及制剂对鱼害粘球菌、肠型点状气单胞菌和荧光假单胞菌均有一定的抑菌作用,两种药物协同抑菌作用明显。杜仲提取物、大蒜素及其复方制剂对肠型点状气单胞菌和荧光假单胞菌均有一定的杀菌作用,仅1∶2复方对鱼害粘球菌有杀菌作用。两种药物复方的杀菌作用,既有协同也有拮抗作用。     

海南森林溪流淡水鱼类区系及动物地理初报

从 1998年 5目至 2 0 0 1年 10月 ,在海南岛森林溪流中实际采集到 4 0种淡水鱼 ,分别隶属于 5目 15科34属 ,分属五个区系复合体 ,其中热带平原鱼类复合体有 2 3种 ,占 5 7 5 % ,中印山区鱼类区系复合体 10种 ,占 2 5 % ,分布于昌化江水系 2 3种 ,万泉河水系 2 9种 ,南渡江水系 2 0种 ,分别占总数的 5 7 5 %、 72 5 %、 5 0 %。     

Ancestry and amphidromy in island freshwater fish faunas

Amphidromy is a frequent attribute of fish faunas of remote islands, where the presence of freshwater fishes creates perplexity as to how such remote places came to have ‘freshwater fish’. Not infrequently, the fact that amphidromous species spend part of their lives in the sea is invoked as indicating that such species have marine ancestries, and this is the implied explanation for presence of freshwater fishes on islands. However, examination of the ranges of some amphidromous species, and of the distributions of genera to which amphidromous fishes belong, strongly suggests that amphidromy, especially in the gobies of the subfamily Sicydiinae, is a widespread, probably ancestral trait. Rather than such amphidromous fish having a marine ancestry, their marine life stages are themselves the likely key element in explaining their distributions.