Studies On Cytogenetic And Reproductive Biology Of Loach (Misgurnus Anguillicaudatus) From Poyang Lake

The loach with fat and delicious is a kind of small freshwater fish. It spreads widely and has a great amount. According to investigation, there are various brindled loaches in lake or pond. The preliminary research of selection indicates that it has stable genetic characteristics. The general biological characters, the growth and reproduction of the three kind of brindle loach which distribute in Poyang Lake region were analysed by biochemistry technology, cell and molecular biological manner. All of above was expected to provide the evidence of theory in well-bred loach selection.First, the growth and reproduction of the three different laoch were investigated. According to the blot of their bodies, the loaches of Poyang Lake can be divided into three groups: the big-brindled, small-brindled and non-brindled. The countable and measurable properties, the fatness, the mature coefficient, relative fecundity, as well as the fertilized and the hatching ratio of each group were measured. Data suggest that there are no distinct morphologic differences among the three kinds. But the fatness is quite different between the male and female loaches of the same type. The number of relative fecundity of big-brindled loaches, small-brindled loaches and non-brindled loaches are 682.00± 249.57,439.72± 189.75 and 573.54 ± 127.54 per gram of body, respectively, while the fertilized ratio is 73.5 ± 3.5707%, 67.9± 2.4820%, 71.9± 4.0546% for each and the hatching ratio reaches 95 ± 2.2361%, 85 ± 3.1623%, 93 ± 5.1769% respectively. The relations between-weight and length are W = 0.0077L2.976 (r=0.8425), W = 0.0302xL2.460 (r=0.8032) and W = 0.0753L2.113 (r=0.7324) respectively. The three different kinds of brindles loaches have been cultivated for three generations. The result shows that the big-brindled loaches are better than the other two in breeding performance.Second, the karyotypes of three kind of loach were investigated. The diploid number of this species is 2n=50. The chromosome of the three kinds of loach can be divided into two types: the big-brindled and small-brindled are the same type which consisting of 8 pairs of metacentric, 6 pairs of submetacentric and 36 pairs of telocentric elements. The karyotypes consists of 8m+ 6sm±+36t, NF is 64. The other is non-brinded which consisting of 8 pairs of metacentric , 6...