A Report on Classical Cytogenetics of Hihgfin Barb Fish, Cyclocheilichthys armatus (Cypriniformes, Cyprinidae)

抄録

Conventional staining and Ag-NORs banding techniques were applied on the chromosomes of hihgfin barb fish, Cyclocheilichthys armatus. Specimens were collected from the Chao Phraya River, Thailand. The mitotic chromosome preparations were directly obtained from kidney tissues of eight males and eight females. The results revealed that the diploid chromosome numbers of C. armatus was 2n=50 and the fundamental number (NF) was 94 in both males and females. The karyotype consists of four large metacentric, six large submetacentric, two large acrocentric, eight medium metacentric, 12 medium submetacentric, 12 medium acrocentric and six medium telocentric chromosomes. No sex chromosome was observed. Ag-NORs indicating NORs were clearly exhibited at the region adjacent to telomere of the short arm of some chromosomes. The NORs located on chromosomes of the metacentric chromosome pair 3 and the submetacentric chromosome pair 7. The karyotype formula of C. armatus is 2n=50=L^m₄+L^sm₆+L^a₂+M^m₈+M^sm₁₂+M^a₁₂+M^t₆. Cytogenetic data of cyprinid fishes can be used as the basic knowledge for enhancing the existing cytotaxonomic information and chromosome evolution of the Cyprinidae especially in the genus Cyclocheilichthys.