Abstract

• The deccan carp Labeo potail and striped catfish Pangasianodon hypophthalmus were obtained from Arrthit Private Fish Farm, Patheingyi Township to investigate their chromosomal characteristics by blocking the metaphase stage of mitotic division during January to August 2022. The spreads of metaphase stages of chromosomes were observed in the colchicine concentration 0.50 % for duration 4 hrs 30 mins in L. potail and 5 hrs 30 mins in P. hypophthalmus with 0.56 % hypotonic solution for duration 1 hr. The various organs of fishes were used for chromosome preparation. Karyological analysis revealed that 2n = 56 having 1 m (metacentric) + 3 sm (submetacentric) + 4 a (acrocentric) + 20 t (telocentric) with fundamental arm number (64) in L. potail, and 2n = 60 having 1 m (metacentric) + 8 sm (submetacentric) + 4 a (acrocentric) + 17 t (telocentric) with fundamental arm number (78) in P. hypophthalmus. The best metaphase spreads of chromosomes were observed in kidney and gill filaments compared with the liver, blood cells and oral cells in both of the fish species.