Morphological variations among Schizothorax species from Kashmir Himalayas

Abstract

This study investigates the morphological variation among Schizothorax species in the Kashmir Himalayas using geometric morphometric techniques. Schizothorax species, commonly known as snowtrouts, are vital to the aquatic ecosystems and fisheries of the Himalayan region. Despite extensive taxonomic research, significant ambiguity remains regarding species delineation due to hybridization and environmental influences. A total of 111 Schizothorax specimens were collected from the River Jhelum. Eleven anatomical landmarks and five semi-landmarks were identified and digitized using tps Dig software. The results revealed significant shape differences among four Schizothorax species, primarily in the head and body regions. Canonical Variate Analysis (CVA) demonstrated a clear separation of Schizothorax esocinus and Schizothorax labiatus from Schizothorax niger and Schizothorax curvifrons, although some overlap was observed between the latter two species. Discriminant Function Analysis validated these findings with a 97 % correct classification rate. The study underscores the effectiveness of geometric morphometrics in distinguishing closely related species and understanding their morphological adaptations. These findings provide critical insights for biodiversity conservation and fisheries management in the Kashmir Himalayas, emphasizing the need for integrated taxonomic, genetic, and ecological approaches to resolve species ambiguities and support sustainable management practices.