Geographic Morphometric Variations of Freshwater Murrel, Channa punctatus from Northern and Eastern Parts of India

Abstract

Significant variations in the multivariate morphometric analysis were observed in the sub-populations of freshwater murrel, Channa punctatus from two habitats characterized by different environmental conditions. A linear relationship was noted between different body measurements and total length of the fish in both the environments. The 14 morphometric parameters found to be significant (p < 0.05) in univariate (one way ANOVA) analysis were further subjected to multivariate analysis using principal component and discriminant function analysis. Principal component analysis indicated shape variation and accounted for 76 % of the total variance. In discriminant function analysis of the significantly different morphometric parameters, 96.9 % of cross-validated grouped cases were correctly classified and the sub-populations were discriminated. Parameters like dorsal fin length, snout length, inter-orbital length, pre-anal length, head length, pre-dorsal length and pre pectoral length were mainly responsible for variations and discrimination between the sub-populations in the discriminant function analysis. The fish from the two environments also deviated from the so called cube law which indicated the different growth rate in length-weight relationship study. Significant divergence in morphometric analysis revealed that intraspecific variations existed between the two sub-populations of C. punctatus. Therefore, these findings indicate the presence of two different stocks of C. punctatus.