Karyomorphological studies from mitotic metaphases in three carp species

Abstract

Karyological analysis of three carp species viz. Ctenopharyngodon idella, Hypophthalmichthyes molitrix, and Cyprinus carpio communis belonging to family Cyprinidae was carried out. The study samples of these species were collected from local fish farm in Haryana. The diploid chromosome number in C. idella was found to be 2n = 48, with 13 pairs of metacentric, 3 pairs of submetacentric and 8 pairs of acrocentric chromosomes. Chromosomal studies on the H. molitrix revealed the diploid chromosome number to be 2n = 48, with 6 pairs of metacentric, 6 pairs of submetacentric and 12 pairs of acrocentric chromosomes. The diploid chromosome number in C. c. communis was found to be 2n = 100, with 17 pairs of metacentric, 3 pairs of submetacentric, 1 pair of subtelocentric and 29 pairs of acrocentric chromosomes. Arm ratio, centromeric index and fundamental number of arms was also determined. The study reveals that diversification in these carp species of cyprinidae family is related to structural changes in chromosomes. Habitat conditions and anthropogenic activities might be responsible for incidence of pericentric inversions causing karyomorphological changes and thereby variation in karytype formulae vis-a-vis earlier reports.