STUDIES ON THE KARYOTYPES OF CHINESE CYPRINID FISHES II. KARYOTYPES OF FOUR SPECIES OF XENOCYPRIMNAE

The karyotypes of four species of fishes belonging to the subfamily Xenocyprininae were investigated in cultured kidney cells by thhe conventional technique. These four species are identified as Xenocypris argentea, Xenocypris davidi, Plagiognathops microlepis and Ac-anthobrama simoni. The fishes used in this study were obtained from the market in Shashi Municipality and Wuhan City and some of them were collected from the Long Lake near Shashi City, Hubei Province.All of these four species have a diploid chromosome number (2n) of 48 with fundamental numbers (NF) amounting to 92 or 94.X. davddi, P. microlepis and A. simoni possess a common karyotype consisting of 9 pairs of metacentrics, 13 paris of submetacentirics and 2 pairs of subtelocentrics, while the karyotype of X. argentea comprises 10 pairs of metacentrics, 13 pairs of submetacentrics and 1 pair of subtelocentrics. A pair of obviously large chromosomes were observed in these fishes.There are some common karyologic features found present among the species of Xe-nocyprininae and also among the species of Abramidinae as reported. All of them have: (1) a diploid chromosome number of 48; (2) a similar karyotype formula of 14 - 20m+ 24 - 28sm+2 - 8st; and (3) a pair of obviously large chromosomes. These common features suggest that these two subfamilies may descend from a common origin.