Morphological Differentiation Between Riverine and Lacustrine Populations of Snow Trout Schizopyge niger (Cyprinidae) from Kashmir using Truss Morphometry

Landmark-based morphometrics are examined to evaluate the population status of Schizopyge niger (Heckel, 1838) from Dal Lake and Jhelum River. A total of 180 individuals are collected from the two locations, and a truss network is constructed by interconnecting 12 landmarks to yield 30 distance variables that are extracted from digital images of specimens using tpsDig2 and PAST software. Transformed truss measurements are subjected to Principal Component Analysis (PCA), where the first component explains 78.43% of total variance, while the second and third components explain 4.62 and 2.91% of total variance respectively. The high component loadings are from the characters which mostly contribute to anterior half of body depth, middle portion of body depth, and head region. The bivariate plot of PC1 and PC2 clearly indicates the separation of the two populations. The cross validation of this analysis reveals that the percentage of correctly classified fishes is 100% both in Dal Lake as well as Jhelum River.