Abstract:In order to investigate the cytogenetic characters of Megalobrama pellegrini,the karyotype and DNA content were studied in the present study.The chromosome number and karyotype were analyzed by a routine method including intraperitoneal injection of PHA and colchicine,cultivation invivo,and slides preparation with air-drying and Giemsa staining.The results showed that M.pellegrini had a chromosome number of 48 (2n=48),with a large and long chromosome pair and no heterosome,and the karyotype was 2n=24m+20sm+4st,NF=92.Erythrocyte nuclear DNA content of M.pellegrini was determined by flow cytometry using the chicken erythrocytes (DNA content is 2.30 pg) as a standard.The DNA content of M.pellegrini is 2.82 pg and the ratio of DNA content between M.pellegrini and chicken is 1.23.