Feeding ecology and digestive enzyme activity of Chirruh snowtrout, Schizothorax esocinus (Cypriniformes, Cyprinidae), from the River Jhelum, Kashmir
Abstract
We examined the feeding ecology and digestive enzyme activity of Chirruh snowtrout, Schizothorax esocinus, (Heckel, 1838), from three reaches of the Jhelum River (Safakadal, Amira Kadal and Zero Bridge) over 12 months. Gut-content analysis indicated an omnivorous diet dominated by plant material (63.61%) with a substantial animal component (35.25%). Diatoms were the single most abundant category (39.65%), followed by crustaceans (27.70%), macrophytes (12.64%), green algae (6.64%), and blue-green algae (4.68%), with other items comprising 8.69%. Feeding intensity peaked in June–August and was lowest from January–April. Across seasons, mean digestive enzyme activities were α-amylase 110.45 U/L, trypsin 0.96 U mg–1 protein, lipase 57.48 U/L, and alkaline phosphatase 58.98 U mg–1 protein, with trypsin, α-amylase, and lipase showing their highest seasonal values in autumn, while alkaline phosphatase peaked in summer; α-amylase showed its lowest seasonal value in spring. Together, these results clarify trophic strategy and digestive capacity in S. esocinus and suggest seasonal tuning of enzymatic function consistent with observed dietary shifts. Findings inform natural resource management and support feed formulation strategies for related aquaculture applications.
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