抄録
The first chromosomal characteristic of nucleolar organizer regions/NORs and karyological analysis of the royal knifefish (Chitala blanci) from Mekong River, northeast Thailand, were studied. Kidney cell samples were taken from one male and one female fish. The mitotic chromosome preparations were done directly from kidney cells. Conventional and Ag-NOR staining techniques were applied to stain the chromosomes. The results showed that the diploid chromosome number of C. blanci was 2n=42, the fundamental numbers (NF) were 42 in both male and female. The types of chromosomes were 12 large telocentric and 30 medium telocentric chromosomes. The Ag-NOR banding indicated that a single pair of NORs was observed on the long arm centromeric region of medium telocentric chromosome pair 10. The karyotype formula could be deduced as:
2n (diploid) 42=L12t+M30t
