Cytogenetic characterization of Devario aequipinnatus (McClelland, 1839) and Devario yuensis (Arunkumar and Tombi, 1998) (Cypriniformes: Cyprinidae) from Manipur, northeast India

Cytogenetic characteristics of Devario aequipinnatus (McClelland, 1839) and Devario yuensis (Arunkumar and Tombi, 1998) from northeast India were studied by examining metaphase chromosome spreads from gill, epithelial, and kidney cells. The diploid chromosome numbers of both species were 2n = 50. The karyotypes consisted of 3 pairs of metacentric, 17 pairs of submetacentric, 3 pairs of subtelocentric, and 2 pairs of acrocentric chromosomes having the arm numbers NF = 96 in D. aequipinnatus; and 5 pairs of metacentric, 13 pairs of submetacentric, 6 pairs of subtelocentric, and 1 pair of acrocentric chromosomes having the fundamental arm numbers NF = 98 in D. yuensis. No sex chromosomes were detected cytologically in either of the species. The present study is the first report on the karyology of these 2 species from northeast India. Comparison of the chromosome numbers of these 2 fishes with those of other members of closely related genera of the subfamily Danioninae shows that 2n = 50 could be considered as a modal diploid chromosome number in this fish subfamily.