SEXUAL DIMORPHISM AND BODY SHAPE ANALYSIS OF GONGOTA LOACH, CANTHOPHRYS GONGOTA (HAMILTON, 1822) USING LANDMARK-BASED GEOMETRIC MORPHOMETRICS FROM THE ATRAI RIVER, DINAJPUR, BANGLADESH

Abstract

Geometric morphometric method was used to examine sexual dimorphism and body shape variations between the sexes of Canthophrys gongota. A total of 128 (64 male and 64 female) individual of this species was collected from the Atrai river in Dinajpur district of Bangladesh. Shape data was extracted by recording 24 landmark points on two dimentionals pictures of specimens. Sexual dimorphism was found through MANOVA and ANOSIM analysis in PAST software. Discriminant function analysis (DFA) showed little overlapping of plots which were remarkably separated 99.22% the male from female. The findings in the discriminnant function analysis showed substantial variance between body shape of the sexes where female exhibited wider abdomen than male. Relative warp scores analysis indicated variation on head region, pectoral and pelvic fins between both sexes. The canonical variate analysis (CVA) scatterplots also illustrated the sexual dimorphism in the body shape of C. gongota. From this study, sexual dimorphism and variation of morphological structure of C. gongota were determined through the application of geometric morphometrics.