Author(s): Lu Eenhou, Li Yanjuan and Xu Kesheng
Pages: 487-492+502
Year: 1984 Issue:  5
Journal: Oceanologia et Limnologia Sinica
Keyword:  异形染色体对; 团头鲂; 有丝分裂相; 特殊染色体; 特大; 染色体组型; 小型染色体; 水生生物; 相对长度; 团头舫;
Abstract: Numbers of chromosome of mcyalobrama amblycephala Yih have been reported differently in papers published in recent years. Our observations of peripheral blood leukocytes collected from both sexes reveal:The diploid chromosome number is 2n=48.The karyotype consists of 8 pairs of metacentric chromosomes, 12 pairs of subme-tacentric chromosomes, 3 pairs of subtelocentric chromosomes and 1 pair of "special chromosomes". The "special chromosome pair" may consist of a pair of megachromo-somes in some individuals, or a pair of heteromorphic chromosomes--one megachro-mosome and one small chromosome-in others. The megachromosome or heterochro-mosome pair occurred in both sexes, obviously, they are not sex-chromosomes. The origin of the "special chromosome pair" is discussed.The secondary constrictions and satellites were only observed in some chromosomes of a few metaphase plates.