Silver staining technique (Ag-NOR banding) which detect active NORs was introduced to study the chromosome of many fish species in several families such as Cyprinidae (Nagpure et al. 2001), Channidae (Khuda-Bukhsh and Barat 1987, Khakhong et al. 2014), Osphronimidae (FurgalaSelezniow et al. 2008). In Channa, the numbers of NORbearing chromosomes va