Pattern of morphological variations in Alghad snowtrout, Schizopyge niger (Heckel 1838) from Kashmir Himalaya, using truss network analysis

Abstract

A total of 278 Schizopyge niger (Alghad snowtrout) samples were collected from three water bodies of Kashmir Himalaya and studied for body shape morphometrics. The truss method was used to generate 21 morphometrics from 11 landmarks using the software applications tpsUtil, tpsDig2 version 2.1 and PAST. The allometrically transformed truss measurements were subjected to factor analysis, classification by cross validation of discriminant function analysis and univariate analysis of variance. The step-wise discriminant function analysis retained two variables that significantly discriminated the populations. Head and body depth morphometrics had high-magnitude loadings on the first factor, and those from the caudal peduncle had high-magnitude loadings on the second factor. Using these variables, 90.6 % of the original groups were classified into their correct samples and 89.2 % of the cross-validated groups omitting one procedure were classified into their correct samples. Slight overlapping was observed between the samples of River Jhelum and Lidder (17.9 %). The occurrence of separate stocks may be the result of changing physical and ecological conditions of water bodies in Kashmir Himalaya.