KARYOTYPES OF Opsariichthys bidens AND Misgurnus anguillicaudatus(PISCES), WITH A CONSIDERATION OF THE RELATIONSHIP BETWEEN POLYMORPHISM OF CHROMOSOME NUMBER AND TAXONOMY OF FISH
Li Yucheng and Li Kang
Opsariichthys bidens and Misgurnus anguillicaudatus, collected from Yaan, Leshan and Chongqing, Luzhou in Sichuan Province respectively, were karyotypied. O. bidens has 2n of 74, while M. anguillicaudatus possesses 2n of 50. In contrast, the other fishes of O. bidens and M. anguillicaudatus, collected in Guangdongand Hubei Provinces and karyotypied by us previously, have different chromosome numbers, e. g. 2n of 76 and 100 respectively. All the results indicate that polymorphism of chromosome number occured in these two species of fishes. The Chromosomal polymorphism of O. bidens might have resulted from Robertsonian translocation; and the chromosomal polymorphism of M. anguillicaudatus was probably caused by karyotypical duplication from diploid to tetraploid. The populations with different karyotypes of these fishes might be considered as independent species or subspecies and the karyotypical cha racteristics might be used as criteria of taxonomy.