Schizothorax esocinus (Heckel, 1838) in Dal Lake and Jhelum River: physiological traits and population trends in the Kashmir Himalayas

This study investigated the physico-chemical characteristics of Dal Lake and the Jhelum River along with evaluation of the morphometric traits, biometric growth parameters, biological indices, physiological attributes, and biochemical profiles of Schizothorax esocinus populations inhabiting these freshwater systems. The physico-chemical assessment revealed distinct environmental differences between the two habitats, with Dal Lake characterised by relatively warmer water, greater hardness, near-neutral pH, and comparatively lower dissolved oxygen levels than the Jhelum River. Correspondingly, fish from the Jhelum River exhibited greater body size and weight, whereas individuals from Dal Lake showed comparatively smaller morphometric dimensions. Biometric growth analysis indicated positive allometric growth in both populations, with notable variations in growth patterns between the two habitats. Biological indices differed between sites and sexes, reflecting habitat specific reproductive and metabolic conditions. Although haematological parameters showed no marked genderbased differences; however, site and age-related variations were evident, suggesting the influence of environmental conditions on physiological status. Overall, the findings highlight habitat driven differences in environmental quality and associated biological responses in S. esocinus, providing valuable insights for conservation planning and sustainable fisheries management in the freshwater ecosystems of Kashmir. Keywords: Aquatic environment, Condition factor, Hematological indices, Morphometric traits, Physico-chemical parameters