鱼类杂交育种试验研究简报

鱼类杂交及基在生产上的应用,在国内外都有报导。我国鱼类杂交工作主要是在鲤科鱼类进行,这与我国传统的养殖对象大多属于鲤科鱼类有关。通过鱼类远缘或种内杂交可以获得“杂种优势”,或培育新的优良品种。鱼类杂交育种需要的周期长,由于鱼是生活在水体里,不便观察,且容易逃散,若无严格的管理制度和科学的养殖方法,往往是半途而废的。     

罗非鱼种间杂交产生全雄性后代的原理

近年来，我国在研究推广罗非鱼全雄性杂交种养殖中，成绩显，获得广大养殖户的欢迎。生产实践结果表明，包括奥尼杂种(俗称奥尼鱼)和莫尼杂种(俗称福寿鱼)在内的罗非鱼杂交种，具有个体大、生长快、产量高和抗病力强的特点，显示出鱼类杂交的优势。特别是奥尼杂交种后代，都是95％以上的雄性，养殖这种雄性罗非鱼，     

鳙、鲢杂交种的形态学研究

鳙、鲢是我国主要的淡水养殖鱼类,有关它们的鳃耙(方秉文)、鳞片、咽骨、咽齿(朱元鼎;王应天等)和消化道(倪达书和蒋燮治;林浩然)结构的研究,过去曾有一些报道,孟庆闻和苏锦祥对白鲢作了系统的解剖。1958年秋季,我们在杭州上城河利用鳙(Aristichthys nobils)×鲢(Hypophthalmichthys molitrix)得到鳙、鲢杂交种,杂交子裔大多生长发育良好。为了对鳙、鲢杂交种作进一步的了解,近年来,我们就杂交种和鳙、鲢纯种的外部形态、骨骼、消化道及鳔等进行形态学的比较研究。杂交种在部分养殖场已经试行生产,因此先作这样的基础研究,为进一步开展对这一新品种的研究是有     

鲷科于类属间远缘杂交的发育和生长

鲷科鱼类的肉味鲜美 ,营养价值高 ,生长快 ,其主要养殖品种真鲷 (Ｐａｇｒｏｓｏｍｕｓｍａｊｏｒ)、黑鲷 (Ｓｐａｒｕｓｍａｃｒｏ ｃｅｐｈａｌｕｓ)、黄鳍鲷 (Ｓｐａｒｕｓｌａｔｕｓ)和平鲷 (Ｒｈａｂｄｏｓａｒｇｕｓｓａｒ ｂａ)的人工繁殖及种苗生产已获得成功[1,2 ] ,但未见其杂交育种成功的研究报道。这 4种鲷分属同科不同属。笔者从1 989年开始进行这 4种鲷的杂交育种生产试验 ,均成功孵化出杂种仔鱼 ,并获得全长 6 6～ 86ｍｍ的平鲷与黑鲷杂交后代幼鱼 6 .0万尾。为海水鱼的属间远缘杂交研究及杂交育种生产提供了理论和技术依据1…     

中国鲇形目鱼类核型研究进展

开展鱼类核型分析对鱼类的遗传、变异、分类、系统演化、性别决定、杂交育种以及环境污染监测等研究具有重要意义.鲇形目鱼类在我国水产养殖中占有重要地位,同时也是研究鱼类染色体进化与性染色体分化的良好材料.本文综述了我国35种鲇形目鱼类及其杂交子一代和多倍体的核型研究进展,分析了不同类群中的核型特征,并对部分类群的染色体进化关...     

鱼类杂交育种技术及其在石斑鱼类中的应用

综述了鱼类杂交育种的发展和远缘杂交的应用,以及遗传学在鱼类杂交育种中的应用,并从遗传学角度对石斑鱼类杂交育种的研究现状进行了介绍,简述了通过杂交和选育等遗传育种技术改良种质,获得石斑鱼类优良新品种。将遗传学分析应用于石斑鱼类杂交的研究中,展望了石斑鱼类杂交育种工作的前景。     

几种杂交鲤鱼经济性状的研究

<正> 鲤鱼(Cyprinus Capio)在我国淡水鱼总产量中占10～30％,它具有地域范围广、适应性及繁殖力强、食性广、味道鲜美等特点,一向为我国人民所喜爱,很早就成为我国主要淡水养殖鱼类。近年来,我国对鲤鱼的遗传、育种工作开展了大量的研究;通过鲤鱼种内不同品种间杂交,利用杂交优势,改变亲本性状,获得生长快,增肉率高、养殖周期短、抗病力强、起捕率高等杂交后代,已选育出不少鲤鱼杂交种。     

七彩鲑(♂)与虹鳟(♀)杂交苗的形态学观察及生长、抗病试验

<正>在我国,鱼类的杂交育种技术作为培育鱼类新品种的基本方法之一在20世纪中叶就开始应用。几十年来获得了许多具有养殖意义的新品种,以鲤鱼不同品种或品系间的杂交最为突出,如丰鲤、荷元鲤,三杂交鲤等,杂交优势明显,育成的建鲤和松浦鲤等新品种,取得了显著的经济效益。七彩鲑、虹鳟同属鲑科(Salmonidae),分别为     

罗氏沼虾品种改良研究

引进天然水域的野生原种罗氏沼虾F1代（下称野生种）进行养殖，并和我所20多年前引进的罗氏沼虾后代的养殖群体（下称养殖种）分别进行自繁和杂交育种试验。结果表明，野生种和养殖种正反杂交所繁殖的后代（下称杂交种）在育苗和养殖效果上都明显优于它们的自繁后代，杂交种在体质、活力、抗病力、成活率及生长等方面都显示了较大的优势。引进野生种或用野生种后代和养殖种进行交配繁殖，获得杂交优势，是罗氏沼虾品种改良的重要手段。     

饲料蛋白质含量对杂交条纹鲈生长的影响

杂交条纹鲈是指条纹鲈 (ＭｏｒｏｎｅＳａｘａｔｉｌｉｓ)和白鲈 (Ｍ .Ｃｈｒｙｓｏｐｓ)的杂交种。 6 0年代中期 ,在美国加州用条纹鲈的卵子和白鲈的精子生产出杂交条纹鲈 (又称棕榈鲈 ) ,另一种相对应的杂交种称为阳光鲈。 80年代末 ,在美国东南部开始养殖杂交条纹鲈并迅速发展成为一项主要的水产养殖产业。杂交条纹鲈适宜养殖水温为 4～ 33℃ ,最适生长水温为 2 5～ 2 7℃。能在各种盐度的水体生长 ,最适溶氧为 6～ 12ｍｇ/Ｌ ,ｐＨ为 7 0～ 7 5。杂交条纹鲈终生为肉食性鱼类 ,在人工饲养条件下亦可摄食配合饲料。该鱼具有显著的杂交生长…     

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.     

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).     

Involvement of gonadal steroids in final oocyte maturation of white perch (Morone americana) and white bass (M. chrysops): in vivo and in vitro studies

Plasma estradiol-17 (E₂), testosterone (T), 17,20-dihydroxy-4-pregnen-3-one (DHP) and 17,20,21-tri-hydroxy-4-pregnen-3-one (20-S) levels were measured by radioimmunoassay (RIA) in white perch (Morone americana) and white bass (M. chrysops) that were induced to undergo final oocyte maturation (FOM) with human chorionic gonadotropin (hCG). Plasma DHP levels increased in females of both species in association with oocyte germinal vesicle migration (GVM) and germinal vesicle breakdown (GVBD) and decreased thereafter. Plasma 20-S levels also increased with oocyte GVM in white bass, but were several-fold lower than DHP levels. Circulating E₂ and T levels were greatest during GVM and GVBD in both species and decreased to low levels during oocyte hydration and ovulation. Follicles from white perch and white bass which received a priming injection of hCG in vivo, produced both DHP and 20-S in vitro after exposure to hCG and their oocytes underwent GVBD. Ovarian incubates from unprimed fish of either species produced only E₂ and T and their oocytes did not complete GVBD. Oocytes from unprimed bass, but not perch, matured when follicles were exposed to hCG in vitro. Both trilostane and cycloheximide blocked in vitro production of DHP and 20-S and oocyte GVBD by white perch follices. DHP and 20-S were equipotent inducers of FOM in the GVBD bioassay. None of several other structurally-related steroids tested were effective within a physiological range of concentrations. These results indicate a role for DHP and 20-S in the control of FOM in white perch and white bass.     

Cardiac,ventilatory and metabolic responses of two ecologically dissimilar species of fish to waterborne cyanide

Changes in heart rate, ventilatory activity and oxygen consumption were determined in trout (Salmo gairdneri) and brown bullhead catfish (Ictalurus nebulosus) during exposure to a steadily increasing concentration of waterborne cyanide selected to produce death in 8–9 hours for each species. The lethal cyanide concentration for the bullheads was an order of magnitude higher than for trout. Trout developed an immediate and gradually increasing bradycardia throughout the exposure period. Cyanide produced tachycardia in the bullhead followed by a gradual onset of bradycardia as the concentration of cyanide was raised. Pericardial injection of atropine (a muscarinic cholinergic antagonist) indicated that bradycardia in the trout was due initially to increased vagal tone but later due to the direct effect of cyanide on the heart. Hyperventilation in the trout persisted throughout the exposure period, although the rate and amplitude fluctuated and was variable between individual fish. During the last hour of exposure (highest cyanide concentration), ventilation was characterized by rapid, shallow breaths followed by a sudden respiratory arrest. The bullheads exhibited hyperventilation during the first 3 hours of exposure followed by a gradual, linear drop in ventilation rate and amplitude until death occurred. Cardiac and ventilatory responses in both species were attributed to stimulation of central and peripheral chemoreceptors by cyanide. Evidence is presented which suggests the initial response in the bullheads was due, at least in part, to gustatory stimulation by the cyanide. Oxygen consumption of the trout remained above pre-exposure levels for the majority of the test period. Oxygen consumption in the bullhead paralleled the changes in heart and ventilatory rates. Whole-body lactate levels of fingerlings of both species during cyanide exposure were measured to estimate the extent of anaerobiosis. Whole-body lactate levels were much greater in the bullheads than the trout, indicating a higher capacity for anaerobiosis, possibly due to a greater fuel supply. Overall, the trout responded to cyanide in a manner similar to that produced by environmental hypoxia whereas the bullheads experienced a gustatory stimulus which masked the hypoxia-like response.     

An overview of stress physiology of fish transport: changes in water quality as a function of transport duration

This study brings an integrated analysis about the relationship between water deterioration and its physiological consequences in live fish transport. The analysis was focused on the transport water and its deterioration, and physiological challenges imposed on the fish. Usual commercial handling procedures employed to mitigate fish stress during transport were discussed. Future topics of research for the establishment of safer fish transport protocols were proposed. Transport was classified into short (≤8 h) or long transport (>8 h). The main issue in short transports should be the prevention of water pH reduction, while in long transports it is the increase in ammonia. Plasma cortisol is the most employed marker for stress and is acutely elevated upon short episodes of transport, but remains elevated even in long‐transport events. Plasma glucose is perhaps a better marker for handling stress. Plasma lactate, pH, osmolality CO₂ and ions should be more often evaluated. Plasma Na⁺ and Cl^‐ are very useful markers of acidosis, due to their respective exchange for H⁺ and , for acid–base regulation. The establishment of species‐specific transport protocols should be preceded by such combined analyses of water and physiological parameters.