黑龙江银鲫的性别控制和无性生殖系的研究

用方正银鲫()×镜鲤()所产生的全雌性后代的一部份幼鱼,投以95％酒精作性诱导剂的配制饲料,使幼鱼性转化为生理雄鱼。转化率在84％以上。此法开始处理的时间是在孵化后16—17天,处理的持续时间为30—40天。3年来,从性转化的生理雄鱼与方正银鲫雌鱼获得了无性生殖系一代,然后再从此一代获得了无性生殖系二代,以此建立了方正银鲫纯系。根据后代形态学指标、染色体数和红血球体积等确定,后代与亲本完全相似,并由此确定方正银鲫的性别决定机制,雌性为XX型,雄性为XY型。     

厦门附近几种浮游甲壳动物的化学成分

1.本文分析的几种海洋浮游甲壳动物都含有占干物质50％以上的蛋白质,氨基酸的组分也相当完整。其中必需氨基酸的含量相当丰富,特别是色氨酸。如桡足类的色氨酸含量比牛肉多了三分之二。 2.经过加工处理的甲壳动物干制品,无论是蛋白质或必需氨基酸的含量损失不大,基本上保持其原有的营养值。 3.一般浮游甲壳类比底栖型的甲壳类,所含的脂肪多而灰分的含量正相反,这是营浮游生活的一种适应现象。 实验结果表明,以上几种海洋浮游甲壳动物,无论作为人类的食品或其他海洋经济动物的饵料,都具有很高的营养价值,在渔业上具有重大的意义。     

黑龙江银鲫雌雄同体的组织学

从方正银鲫自交繁殖的当年鱼群体中发现约有２％左右的雌雄同体。外形观察两侧性腺的分配和着生方式十分复杂和多样。一般为一侧精巢,另一侧为卵巢,但常见到一侧性腺,精巢和卵巢交替着生,有时则从卵巢旁生出一个球状精巢或囊状组织,但未见精巢旁长出球状卵巢的。组织学观察,两种组织的界限分明,雌雄同体的精巢和卵巢都发育良好。精巢壶腹中充满各时相的精原细胞、精母细胞和精子。卵巢则充满Ⅳ期中的卵母细胞,但与精巢交接处的卵细胞或进入精巢中少量卵细胞则发育迟缓,一般处于Ⅱ、Ⅲ时相。非常奇特的是：从卵巢旁生长的小囊状组织,一半为精巢,一半为卵巢,精巢发育良好,可见到各时相的精细胞,但卵巢发育不良,大多是Ⅱ、Ⅲ时相的卵细胞。两种组织交接处有膜分隔,同时有血管通过,供两组织营养。     

异育银鲫在我省东部地区获推广

异育银鲫在我省东部地区获推广黑龙江省国营农场总局渔业公司自１９８９年成立以来，为了发展本地区的渔业生产，克服近几年鲤鱼销售市场受“南鱼北调”带来的冲击，探索推广养殖新品种。如革胡子鲶、彭泽鲫、异育银鲫等获得了成功，提高了池塘单产效益。并对异育银鲫的养...     

高体型异育银鲫的养殖情况介绍

高体型异育银鲫(简称高体鲫)是由方正银鲫(黑龙江省方正县双凤水库的银鲫种群)作母本,与父本兴国红鲤进行人工授精后的雌核发育后代。与其他鲫相比,具有食性广,易繁殖、子代不发生性状分离,抗病力强、成活率高,生长快等优点.1989年我库实施国家星火计划"优质苗种基地建设'项目,从中国科学院水生生物研究所引进高体娜夏花鱼种,进行专池培育.在解决了高体娜的人工策殖、苗种培育技术后,进行了几种形式的成负养殖试验.现将养殖结果介绍如下.1鱼种池鑫养试验在6个鱼种池进     

提高异育银鲫养殖效益的途径

异育银鲫是目前淡水养殖的优良鱼类之一,近年来,主、混养异育银鲫的效益有下降趋势。造成异育银鲫养殖效益下降的主要原因一是品种混杂,普遍存在父母本不纯,一些单位甚至将野生鲫当异育银鲫良种出售。二是饲料成本逐年提高,如每千克菜饼从1996年到1998年每年上涨02元,1998年每养1千克鱼的饲料成本已达到6元以上,加上鱼种、地租等费用,总成本至少8元／千克。三是成鱼售价低,特别是秋冬季（9～12月）大规格鱼（200克左右）的售价仅9元／千克,有时低于8元／千克,小规格鱼（150克以下）的售价更低。四是养殖病害增多,发病率高,死亡…     

异育银鲫的人工繁殖育种及养成试验

鲫鱼(Carassius auratus)属鲤科鱼类。长期以来,阻碍鲫鱼成为重要养殖鱼类的原因,是由于其生长缓慢。亚种银鲫的经济性状较鲫鱼优越。在银鲫的不同种群中,黑龙江省方正县双凤水库的银鲫(称方正鲫)种群最好。中国科学院水生所于1975年开展了鲫鱼的选育研究。搞出了由方正鲫为母本,兴国红鲤为父本人工授精     

主养异育银鲫的高效培育鱼种技术

1993年,我们在宝应县水产养殖公司一分场一排二号池进行了异育银鲫为主的高产高效培育鱼种试验,每667平方米(亩)产鱼种818.75公斤,创纯利2408.99元。做法如下。1 池塘条件与放养 池塘面积0.25公顷,水深2.3米,紧靠交通河,水质清新,灌排方便。配备2.2千瓦的4寸潜水泵一台,1.5千瓦叶轮式增氧机一台。放养种类及夏花尾数列于表1,每667平方米共放养19262尾,其中异育银鲫13158尾,占68.3％,详见表 1。     

异精激发银鲫雌核发育所获后代的比较研究

鲫鱼是重要的淡水经济鱼类，广泛分布于欧亚内陆水域。在我国的一些大型湖泊、水库里，鲫鱼一般可占产量的20～40％。黑龙江水系产的银鲫(2n=156±)，因具有多种优良性状，尤有重要的经济意义。     

Herpesviral haematopoietic necrosis of goldfish, Carassius auratus (L.)

Abstract. In the spring of 1992 and 1993, an epizootic with severe mortality occurred among cultured goldfish. Carassius auratus (L.), in Aichi and Nara Prefectures in Japan. A herpes-virus was isolated from moribund goldfish that induced cytopathic effects in FHM and EPC cells. The isolate was sensitive to IUdR (5-iodo-2-deoxyuridine), acid (pH 3) and ether. Transmission studies confirmed the pathogenicity of the viral isolate for goldfish while it was not pathogenic for fancy carp, Cyprinus carpio L. Diseased fish had no visible external signs except for listlessness, but internally there was softening and discolouration of the spleen and kidney, and necrotic foci in the haematopoietic tissue, splenic pulp, pancreas, and lamina propria and submucosa of the intestine. Electron microscopy revealed enveloped visions ranging from 170 to 220nm in diameter with hexagonal nucleocapsids (115–117nm edge-to-edge diameter). The disease has been designated as herpesviral haematopoietic necrosis (HVHN), and to date, is the only herpesvirus infection to be described in goldfish.     

Two iridovirus isolates from Carassius auratus (L.)

Abstract. Two new viruses, goldfish virus-1 (GFV-1) and goldfish virus-2 (GFV-2), were isolated from swimbladder cultures prepared from healthy Carassius auratus (L.). The isolates were sensitive to pH, heat, and chloroform but stable to freezing and thawing. Treatment with IUDR, Feulgen staining and acridine orange staining indicated that the viruses contain double-stranded DNA. Electron microscopy revealed enveloped virions of 180 nm enclosing icosahedral capsids of 120 nm. Viral growth was studied by light and electron microscopy and infectivity assays. Virions were assembled in cytoplasmic inclusion bodies and apparently released through cell degeneration. Infectious virus was first produced at 24 h post-infection. Progressive cytopathology was observed leading to cell ghosts by 96 h post-infection. The results suggest tentative placement of the viruses in the family Iridoviridae.     

Visceral necrosis of goldfish, Carassius auratus (L.): a new bacterial disease

Abstract. Recent shipments of goldfish into Canada have suffered major mortality within a short time of arrival. The pathology and bacteriology of several of these diseased fish are described. Lesions were either acute and necrotizing with haemorrhage, or they were granulomatous. In either case, the spleen was a prime target, although in severely affected animals other organs were similarly involved; these included anterior and posterior kidney (plus endocrine elements), liver, intestine, mesentery and brain. Associated with these lesions were intracellular bacteria, which were often arranged in a Chinese letters-like configuration, and which are presumed to be the cause of the disease. The Gram-negative bacterium was isolated from all fish, but its characteristics were such that it was not easily classified and its taxonomy therefore remains uncertain.