A karyotype study in two fish species belonging to Genus Neolissochilus found in Meghalaya, India

Abstract

The karyomorphological study of two species of Mahseer belonging to the genus Neolissochilus, namely Neolissochilus hexagonolepis and N. hexastichus were carried out. The study revealed the basic chromosome number in both the Masheer species was observed to be 100. However, the karyotype formula number varied among the species. N. hexagonolepis had a diploid chromosome number of 42 metacentric (m), 20 submetacentric (sm), 8 subtelocentric (st) and 30 telocentric (t) and N. hexastichus had a karyotypic formula of 32 metacentric (m), 22 submetacentric (sm), 4 subtelocentric (st) and 42 telocentric (t). This finding removed taxonomic confusion due to the differences in the chromosome number, the morphology of the chromosomes and chromosome formula between the two fish species of the genus and helped in distinctive and unblemished identification of the two species belonging to the genus Neolissochilus from Meghalaya, though they have a morphological similarity.