Chromosome analysis in three species of fishes belonging to family Gobiidae

Abstract

Caryotype analysis, metrical study and centromeric index of somatic chromosomes from the kidney of three gobiid fishes, Boleophthalmus glaucus, Glossogobius giuris and Gobioides rubicundus and the meiotic chromosomes from the testes of first two species have been investigated. All the three species have 2n=46 chromosomes but the morphology and the metrical data were different. B. glaucus had chromosome formula of 6m+10sm+1st+4t+2T and the measurement of the chromosomes ranging between 2.99±0.55 and 1.34±0.15 micra, G. giuris had 2t+21T and measurement between 2.35±0.35 and 1.30±0.17 and G. rubicundus had 1m+13s+5st+3t+1T and measurement between 2.66±0.32 and 1.59±0.11 micra. No clear indication of sex chromosomes was found either in the somatic or in the germinal cells. Meiosis was stereotype with the bivalents clearly seen from the diakinesis stage. Chromosomal evolution and interrelationships in the three species have been discussed and the role of pericentric inversion in bringing the morphological differences in the caryotype has been stressed.