Stock identification of the Channa striata Inhabiting the Gangetic River System using Truss Morphometry

Resumo

Landmark-based truss morphometry was used to identify stock structure of striped snakehead, Channa striata, in the river Ganga and its tributaries: river Yamuna and river Gomti. The fish samples were collected from Narora site of the river Ganga, Agra site of the river Yamuna and Lucknow site of the river Gomti from November 2012 to May 2016. Ten morphometric landmarks were selected to construct truss network on the fish body. Transformed truss network measurements were subjected to principal component analysis, discriminant function analysis and univariate analysis of variance. The first principal component (PC I) explained 40.2% of total variation while PC II and PC III explained 9.86 and 6.68%, respectively. The step-wise discriminant function analysis retained six variables that significantly discriminated the populations. Using these variables, 89.2% were correctly classified into their original groups. Of the total 35 transformed morphometric measurements, 28 exhibited significant differences among the populations. Results indicate the presence of different stocks of C. striata in the selected rivers of the Gangetic river system.