摘要: Fishes play important roles in many research fields, such as pollution detection of water, biological accumulation of chemicals in the water and biomedicine. Fishes as laboratory animals have been given close attention by numerous researchers. But the research level is less developed and the standardized fishes strains are scarce. Our country have paid more attention to the research and application of fishes as laboratory animals, and made more efforts on the strains selection and culture. In 1987 the agriculture ministry of China started a program of researching on aquaculture experimental animal. At the beginning of 1990s Institute of hydrobiology of the Chinese Academy of Science researched on Gobiocypris rarus for being developed as a laboratory animal, which next study is focus on gynogenesis, strains select, biological and genetics background. Also Carassius auratus red Vaiety is possibly developed as a laboratory animal. Swordtail ( xiphophorus helleri ) is a kind of small tropical freshwater belonging to the Poeciliidae Family. With the characteristics of small body, omnivorousness, easy breeding, short propagation period, and strong productive capacity, large quantity of individuals can be obtained in a short period, so swordtail is suitable to be use as aquatic laboratory animals. After over decade's research on swordtail, we have achieved the following progress: (1) Breeding of pure strain:5 strains with different body characteristics have been established, among them RR B strain reaches to 22st generation after the problem of “degeneration of close cross" has been overcome. (2) Biological characters:Some of swordtail's characters, such as its outer form, main anatomical structure, habit, growth, propagation, sex reversion, have been comprehended. Histological pictures of its some organs have also been acquired. (3) Nutrition and diet:Artificial formula feed has been used to raise swordtail instead of fishworm, which setting the foundation for setup of nutritional standard and SPF laboratory fish. (4) Water quality:Water self circulate device for swordtail's culture has been installed. (5) Genetics and its detection:The whole sequence of mitochondria cyt b gene, altogether 1140bp, was analysed. Compared with those of other mitochondria DNA in BLAST and GenBank, the results showed there were high homogeneity between swordtail and other fish. Evolved tree established according to the sequences of cyt b gene form swordtail and other 13 kinds of fish, was consistent with traditional classification position. (6) Diseases and their control:Swordtail suffered from more than 10 kinds of diseases. Some diseases are concerned with pathogenies carried by living baits, imbalance of nutrition, worse of water quality, and degeneration of close cross. Routine treatments for disease of fish cultured in ponds had the same effects on swordtail's diseases. Infectious diseases have been controlled in the artificial culture system of swordtail since living baits is substituted by artificial formula feed. Serological techniques were applied in early supervision of bacterial diseases. (7) Application research:Results of toxicity test on disinfectants (sodium dichloro isocynurate,trichlonx isocynuric acid, coalesect iodine, calcium oxide, chloride of lime, potassium permanganate),insecticide (formalin, trichlorfon, malathion) and heavy metal chromium (potassium bichromate) illustrated that swordtail is a representative experimental fish for the security evaluation of aquaculture drugs, and that swordtail has a good foreground in inspection of contamination of some pesticides and heavy metals. Swordtail with different body character, size and sex can be directionally applied. For example, white male swordtail is suitable to be used as the recommend experimental material on toxicology of organic phosphor pesticides. Mortality rate had a significantly gradient change when swordtail was infected with high virulence, middle virulence and weak virulence bacterial strains, and their symptoms were similar to thos
摘要: As representative member of low class vertebrate and aquatic ecosystem, fishes have high breeding ability with eggs external tertilized and transparent embryos developing synchronously outside the mother. They are used in researches of embryology, enetics, aquatic toxicology, behavioral science and environmental science.Ever since George using experimental gynogenesis method was published in nature in 1981,zebra fish, medaka and other fishes became favorite laboratory animals and played more and more important roles in the studies of genetics and environmental science. In 1990s,Chinese researchers began studying on rare minnow, swordtail, red crucian carp and other fishes as laboratory animals; consequently, a professional subgroup of Chinese Association for Laboratory Animal Sciences named Society of Experimental Aquatic Animal was set up in 2001 to promote researcher in this area. Rare minnow, Gobiocypris rarus , is a small cyprinid fish. Distributing in Hanyuan, Shimian Shuangliu, Dqjiangyan, Pengzhou County in Sichuan province, it is one of the endemic fishes in west China. In order to use rare minnow as laboratory animal, scientists of Institute of Hydrobiology belonging to the Chinese Academy of Sciences (CAS)have done a series of investigation from1990.These works refer to its geographical distribution, habitat, morphology, taxonomy, reproduction, ontogenesis, growth,food,semitiviqto ecological factors, karyotype, isozymes, breed and care, anaesthesia,production of inbred strain, and soon. Rare minnow has been inbred to 20th generation at present, and guidelines for the laboratory culture and care of the fish have been made. This implies the time we produce and use rare minnow as standard animal model is near. As a new laboratory animal, rare minnow has the flowing attributes:(1) The ash is small with adult total length 38 to 85mm,and it is easy to care for.(2) Some individuals get mature when they are 3 months old under favorite culture, and can spawn when they are 4 months old. The generation time is only 4 months.(3) Spawning occurs when water temperature ranges from 14 to 30 degree of centigrade, thus it is easy to obtain eggs in my season in the laboratory.(4) Rare minnow is a continuous batch spawner. Mature females lay several hundred eggs at interval of a few days (mode 4days). This ensures researchers can get large number of eggs spawn by the same female in a shod period.(5) The eggs are adherent and transparent with diameter 1.25 to 1.70mm, which are larger than eggs of zebra fish or medaka. Embryogenensis and organogenesis can be monitored microscopically, and it is feasible to transplant nuclear or othertechnical operate.(6) Development is normal between 13 and 30 degree of centigrade.It is possible to control the speed of ontogenesis by adjusting temperature.(7)The fish has high adaptability to temperature, high CO 2 and low dissolved oxygen. There are 51 literatures on rare minnow presently. Eighteen of them are about biological background or taxonomy, and the other thirty three are papers about using this fish as experimental animal. In complete statistic shows rare minnow has been used in studies on fish disease, genetics, environmental science, embryology, physiology and ecology in more than 10 universities or research institutions in China. Wang Tiehui et al proved that rare minnow is susceptible to Hemorrhagic Virus of Grass Carp (GCHV)L ,suggested the ash may serve as a model of the virus resistance breeding of grass carp 3 with biotechnique methods. Using rare minnow as experimental fish instead of grass carp, investigators overcomes the difficulties brought by big body size, long generation time, short reproductive season, hard to care for and discommodious to obtain research materials, and hence it accelerates the course of the virus resistance breeding. In environmental science research area, many experiments indicated that rare minnow is a suitable test organism for determining toxicity of chemicals and water samples because the fish is very sensitive to heavy metals, pestici