淡水鱼类高温期暴发性流行病的防治

淡水鱼类高温期暴发性流行病是到目前为止我国养鱼史上危害鱼的种类最多、危害鱼的年龄范围最大、流行地区最广、流行季节最长、造成的损失最大的一种     

冬季主要淡水鱼类暴发性流行病的防治

淡水鱼类暴发性流行病是由嗜水气单胞菌、温和气单胞菌、鲁克氏耶尔森氏菌等细菌感染而引起的一种急性传染病,全年均能发生,尤以水温在28℃以上最为流行,在冬季时有发生。总结了多年来发生在苏北、鲁南、河南等地流行于11月下旬到第2年3月上旬间鱼类暴发性流行病的症状和发病特点,并提出了预防和治疗方案。     

淡水鱼类高温期暴发性流行病的防治

淡水鱼类高温期暴发性流行病是到目前为止我国养鱼史上危害鱼的种类最多、危害鱼的年龄范围最大、流行地区最广、流行季节最长、造成的损失最大的一种急性传染病,此病在各地有不同的名称,如腹水病、出血性腹水病、暴发性出血病等。进入高温季节后,此病的发生率更高,危害更     

淡水鱼类暴发性出血病的控制技术

淡水鱼类暴发性出血病又称细菌性败血症,是由嗜水气单胞菌及温和气单胞菌引起。笔者根据多年的经验,对暴发性出血病发病的一些特点及防治方法作了总结,供广大养殖户参考。一、暴发性出血病的症状主要症状是鱼体各器官组织不同程度的出血或充血。外表症状表现为病鱼口腔、头部、     

鱼类暴发性流行病的防治

主要淡水养殖鱼类暴发性流行病,我们最早于1986年10月在崇明县大同养殖场发现,当时引起异育银鲫大批死亡,因病鱼体表充血、腹部膨大、腹腔内有积水、溶血,因此称为异育银鲫溶血性腹水病。随后不仅在上海各郊县流行,至今已在全国近20个省、市广为流行,流行季节也从最初的10月、11     

淡水鱼类暴发性出血病的防治

淡水鱼类暴发性出血病自从在我国出现以后,已成为危害我国淡水鱼类养殖业最为严重的疾病之一。它具有死亡率高、病程短、易复发,在同一季节大面积流行等特点。特别是高温鱼类生长的旺季流行性更强,危害更大。因此我们一定要注意对此病的诊治,防止给渔业生产带来更大的损失。一、病原体根据鱼类诊断学报告,感染该病的主要病菌为嗜水气单胞菌,但在临床检验中还发现与其它病原体共同感染的病例,且带有一定的普遍性。如:温和气单胞菌、弧菌等。这类细菌多为条件致病菌。池塘环境好、鱼体抵抗力强时,病原体虽存在于水体中也不会发病;池塘水质恶化…     

广东淡水养殖鱼类暴发性流行病的防治研究

1989年夏季，珠江三角洲的一些塘鱼养殖区暴发了罕见的以鲮鱼为主的多种养殖鱼类出血性流行病(简称暴发病)。该病来势凶猛，感染种类多，流行范围广，发病季节长。目前，暴发病已涉及了全国许多养鱼地区，它是我国继草鱼病后，又一种严重危害水产养殖的新鱼病。因此，暴发病已引起了国内科研、生产部门的重视，     

鱼类暴发性流行病防治的几点意见

鱼类暴发性流行病防治的几点意见鱼类暴发性流行病（鳊、鲫鱼流行性出血病）是１９８９年以来我国至今为止危害种类最多、年龄范围最大、地区最广、季节最长、死亡率最高的一种鱼病，它给渔业生产造成了巨大的危害。虽然目前已有很多种鱼药可以治疗此病，但在施药过程中，...     

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。     

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...     

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.     

淡水鱼配合饵料的投喂技术

随着淡水鱼养殖密度和产量的逐渐提高,饵料的投入在整个养殖成本中已占主导地位。因此饵料投喂技术的高低会直接影响饵料的转化率和最终的养殖效果。如果投喂不当,即使是一种好的饵料,也不一定获得好的效果,甚至适得其反。一年中饵料投喂应遵循“早开食,抓中间,带两头”的投喂规律,将全年的饵料主要集中在6～9月份,鱼摄食旺盛,生长最快的季节投喂,春季尽量提前投喂,秋季应延长投喂期。     

淡水网箱养鱼能量效益的初步评价

本文分析比较了4种淡水网箱养鱼方式的能量效益。网箱养非鲫的能量转化效率极显著地(P<0.01)大于网箱养鲤成鱼、鲤鱼种,后两者又极显著地(P<0.01)大于网箱培育鲢、鳙鱼种。网箱养非鲫的能量生产力最高,达2.50兆焦/米~2·天,养鲤成鱼、鲤鱼种、鲢鳙鱼种的次之,分别为1.20、0.99及0.31兆焦/米~2·天,为池塘养鱼能量生产力的16～130倍。     

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 %。     

正常鱼体内条件致病菌种类的调查研究

1998 年4 - 6 月, 作者对安徽省六安地区某养殖场正常鱼体内条件致菌种类进行调查。结果共分离到83 株条件致病菌, 经初步鉴定归为8 个菌属, 其中气单胞菌数量最多, 占总菌株数的59-1 % , 且在各种鱼不同组织脏器中和不同水温条件下均能分离到。表明气单胞菌是该养殖场鱼体中存在的主要条件致病菌。其余各菌属所占比例依次为不动杆菌(13-3 % ) 、黄杆菌(10-8 % ) 、肠球菌(6-0 % ) 、假单胞菌(4-8 % ) 、爱德华氏菌(3-6% ) 、变形杆菌(1-2 % )和克雷伯氏菌(1-2 % ) 。药敏试验结果显示治疗该养殖场鱼类气单胞菌感染的首选药物为环丙沙星、丁胺卡那和氯霉素。此外, 池水细菌总数与水温不呈正相关。     

淡水养殖鱼类小瓜虫病及防治措施

<正>小瓜虫病是淡水鱼类普遍流行的一种寄生虫性原虫病,在所有的淡水养殖鱼类中都有发生,常引起鱼苗鱼种大批死亡,给养殖生产造成惨重经济损失。淡水小瓜虫病的病原是多子小瓜虫,因为病鱼体表或鳃上呈现白色小点病变,故又称"白点病"。该病对淡水养殖