Pattern of Meristic and Morphometric Variations Between Wild and Captive Stocks of Endangered Tor putitora (Hamilton 1822) Using Multivariate Statistical Analysis Methods

Abstract

The endangered Tor putitora is a commercially important freshwater cyprinid distributed widely in Himalayan foothills of India and adjacent countries. Despite its extensive distribution, the stock structure of the species is not known. The present study investigates intraspecific variations in wild and captive populations of this species using multivariate statistical tools. A total of 187 specimens were collected; 7 meristic and 25 morphometric characteristics were recorded for each specimen. The standardized data were subjected to a principal component analysis (PCA), discriminant function analysis (DFA) and univariate analysis of variance. Only 22 significant morphometric variables (P < 0.001) were considered for multivariate analysis. By applying PCA six principal components were generated explaining 88.71 % of total variance between the populations. The step-wise DFA retained only one variable showing highest variation in orbit diameter, maximum body depth, minimum body depth, head length, head depth, dorsal fin height and dorsal fin length, clearly discriminating the two populations. Using these variables, 84.5 % of the original groups were classified into their correct samples and 80.7 % of cross validated groups omitting one procedure were classified into their correct samples. The results obtained from this study have strong implications for sustainable management and conservation programme of the species.