Abstract

• Cytogenetic investigation on silver carp Hypophthalmichthys molitrix and silver barb Barbonymus gonionotus belonging to family Cyprinidae from Thatyetkone Fisheries Station, Mandalay Region, was carried out. The optimal effect of colchicine concentration was observed at 0.50 % for duration 5 hrs with 0.56 % hypotonic solution treatment of 1 hr 30 mins period in silver carp and colchicine concentration 0.50 % for 6 hrs with 1 hr duration of hypotonic treatment in silver barb. The diploid chromosome number of silver carp H. molitrix was 2n = 48 with karyotype formula 2 m (metacentric) + 4 sm (submetacentric) + 6 a (acrocentric) + 12 t (telocentric) and fundamental arm number 60. The chromosomal number of silver barb B. gonionotus was 2n = 50 with karyotype formula 1 m (metacentric) + 9 sm (submetacentric) + 2 a (acrocentric) + 12 t (telocentric) and fundamental arm number 68.