Stock delineation in Clupisoma garua (Hamilton, 1822) populations of Ganga riverine system using truss network analysis

Abstract

Stock identification of fish plays a significant role in management of fishery resources. It is considered as the  precursor to species conservation and imperative for declining fish populations. The stock structure of Clupisoma garua (Hamilton, 1822) populations of Ganga riverine system was studied using truss network analysis. A total of 306 fish specimens obtained from river Ganga in Allahabad, Farakka and Triveni were used to construct the truss network. The truss variables were subjected to principal component analysis (PCA) in which the first component explained 46.71% and the second 14.66% representing body depth and caudal regions of fish, respectively. Bivariate plots of PCA and discriminant function (DF) analysis revealed that it is a single continuous stock in the study area of the river Ganga and the misclassification of DF indicated only a marginal morphological difference. The results indicated the need for a uniform management strategy appropriate for population of C. garua in the river Ganga.

Keywords: Catfish, Conservation, Ganga River, PCA, Stock assessment