鲑科鱼类及其养殖状况

本文介绍鲑科鱼类及其主要生物学特点、鲑科鱼类在世界渔业经济中的重要地位和养殖产业技术发展现况。鲑科鱼类属典型的冷水性鱼类,高蛋白、富含不饱和脂肪酸、营养丰富、可食部分大、无肌间刺、易加工,是欧美人民的传统水产食品和重要养殖鱼类。鲑鱼是世界三大养殖鱼类之一,其养殖产量仅在鲤鱼和罗非鱼之后,海水鱼类养殖中,半数以上(54.3%)来自鲑鱼产量。2005年,世界鲑鱼产量280万吨,其中195万吨(69.6%)来自人工养殖。本文也简要叙述了我国鲑鱼养殖的历史和现状,以及在鲑鳟鱼类遗传育种、养殖新品种开发、营养与饲料、病害防治、繁殖期调控等方面的研究进展,并针对我国鲑鳟鱼产业发展存在的问题提出了建议。     

鲑鱼传染性胰脏坏死病临床诊断及检测

鲑鱼传染性胰脏坏死病（infctious pancreatic necrosis in trout,IPN）是鲑科鱼类的一种高度传染性的急性病毒疾病。该病主要病症是胰脏坏死。该病于1940年首次发现于加拿大的鲑科鱼,目前已遍及欧洲、亚洲和美洲等。     

世界鲑科鱼类养殖技术的现状

鲑科鱼类有两个属,即鲑属和大麻哈鱼属。鲑属只有鲑一个种,而大麻哈鱼属则有六个种,即:大麻哈鱼、银大麻哈鱼、大鳞大麻哈鱼、细鳞大麻哈鱼、红大麻哈鱼和马苏大麻哈鱼。本文简要地介绍了当前世界各国养殖鲑科鱼类方面的现状,有助於我们对它有一个整体的了解,也有助於我们开展鲑科鱼类养殖时参考。     

渔业纵览

为促进鲑鱼类增养殖业的持续发展,中国水产学会与北京顺通虹鳟养殖中心定于2005年10月20～22日在北京举办“中日鲑鱼类增养殖技术学术报告会”。会议将邀请日本著名水产学家隆岛史夫先生做学术报告:①世界鲑鱼类的发展趋势与展望;②鲑、鳟鱼类增养殖生物学研究;③鲑鱼类遗传育种新技术。邀请国内专家做学术报告:1.我国鲑鱼类养殖新品种开发及养殖新技术;2.鲑科鱼类流行病学及药物的安全使用;3.鲑鱼类的高效养殖;4.西南地区鲑鱼类养殖现状与发展对策;5.白鲑属鱼类及其增殖途径的探讨;6.云南冷水鱼养殖发展现状及对策。欢迎从事鲑科鱼类科研、…     

鲑鱼类养殖史料

我们查阅国内外有关鲑鱼类方面的资料,目的是为移值大西洋鲑的试验研究提供依据。现将有关资料归纳整理成“大西洋鲑的起源”、“大西洋鲑的生物学”、“鲑鱼类养殖史料”和“大西洋鲑的人工养殖”等文章,供研究鲑鱼类的同行们参考,同时也为发展我国鲑鱼类养殖业积累些基础资料。鱼类养殖是一种古老的技术,中国人在公元前2000年就开始从事鱼类繁殖,在池塘里能够繁殖多种鱼。现在世界上养鱼发达的日本养殖技术就是从中国引进的。蛙鱼类的养殖是在几百年前随着太平洋鲑和大西洋鲑资源量的减少,为了增加和恢复其种群数量而发展起来的。早…     

大豆粕在鲑鳟鱼类饲料中的利用（一）

一、前言 大西洋鲑鱼、太平洋鲑鱼以及虹鳟统称为鲑鳟鱼类。由于他们价位较高,但为相对容易养殖的鱼类,所以成为世界上主要养殖的肉食性鱼类。鲑鱼与鳟鱼可存活于各种不同的养殖环境,某些鳟鱼可在0℃到28℃的水温之间生存,     

几种鲑鳟鱼类摄食习性及投喂技术

鲑鳟鱼是优质的冷水性鱼类 ,欧美国家养殖极为普遍。我国从上世纪 5 0年代开始养殖虹鳟 ,主要集中在北方地区。随着渔业生产技术的不断发展 ,我国鲑鳟鱼类的养殖范围 ,正由北方向南方扩展 ,养殖品种也由单一的虹鳟鱼扩大到金鳟 ,白点鲑 ,银鲑 ,大西洋鲑 ,等等。虽然这些鱼类都属鲑科 ,但是它们摄食习性相差很大 ,在生产中必须采取不同的投喂方式。1　虹鳟。虹鳟是养殖时间最长的鲑科鱼类 ,已经完全驯化。虹鳟性凶猛 ,贪食 ,能在水面、水中和池底摄食 ,抢食激烈 ,有跟人走动索饵习性。投喂时 ,可定点成片地撒投饲料 ,一般站在池埂的中间 ,向…     

鲑科鱼类鱼卵计数方法简介

鲑科鱼类是国际渔业市场上的高档水产品,也是世界范围内最重要的养殖对象之一。我国幅员辽阔,拥有众多适合开展鲑科鱼类人工养殖的自然资源,并且我国还拥有丰富的优质鲑科鱼类种质资源,如哲罗鱼、细鳞鱼和黑龙江茴鱼等。随着人们生活水平的不断提高,对优质鱼类的消费需求日益增多,鲑科鱼类养殖得到了较快发展,并取得了良好的经济效益。目前在东北地区和内蒙古、甘肃、新疆、山东、山西、福建、四川、云南等地鲑科鱼类养殖蓬勃发展。     

静水充氧式三文鱼人工养殖技术

银鲑和大西洋鲑均为鲑科鱼类，目前在市场上人们把鲑鱼统称为三文鱼，三文鱼是北美、欧洲、日本餐桌上最受欢迎的鱼类之一。尤其因其营养价值高、肉味鲜嫩、少脊问刺而被推为制作生鱼片的首选，是闻名世界的名贵鱼类。     

冰水女皇—七彩鲑鱼

七彩鲑鱼（Salvelinusfontinalis），在我国某些地区又被称为美洲红点鲑，是世界上著名的五种鲑鱼之一（其它四种分别是：北极鲑、雷克鲑、多丽鲑和公牛鲑）。七彩鲑鱼主要分布在加拿大东部以及美国东北部大部分水域，是广盐性淡水三文鱼。在加拿大和美国西部山区也有分布。近年来随着人们对七彩鲑鱼越来越多的认识，它也就逐渐被传播到其他国家了，如南美或欧洲很多国家。七彩鲑鱼色彩鲜艳，体质强健，拼抢凶猛，嘴大牙坚，咬合有力，深受钓鱼爱好者的青睐。七彩鲑鱼还具有肉质坚实、味道鲜美、营养丰富的特点。烹、烤、煎、炸、蒸、炖、…     

Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean

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.     

Growth performance,digestive enzyme activity and immune response of Japanese sea bass,Lateolabrax japonicus fed with fructooligosaccharide

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.     

Rare serotype occurrence and PFGE genotypic diversity of Streptococcus agalactiae isolated from tilapia in China

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.     

Evaluation of a Fast Method Based on the Presence of Two Restriction Sites in the Mitochondrial ND5 (mt ND5) Gene for the Identification of Scomber Species

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.     

Growth hormone (GH) and reproduction: a review

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.     

Purification and partial characterization of GtHs (cfLH and cfFSH) from Indian walking catfish (Clarias batrachus) (L.) and development of a homologous ELISA for cfLH

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.     

Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection

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).