ABSTRACT
The Mozambique tilapia (Oreochromis mossambicus) is an economically important freshwater fish species widely cultured across tropical and subtropical regions throughout the world. This species is prone to helminth parasitic infestations that compromise health and productivity. The hepatosomatic index (HSI) serves as a sensitive biomarker reflecting liver condition, nutrient storage, and physiological stress. It was investigated the impact of helminth parasitism on HSI values of O. mossambicus collected from culture ponds at Tamluk. A total of 60 specimens were sampled (30 visibly infected with helminths and 30 non-infected controls). Body weight, liver weight, and HSI were recorded. The liver and associated organs were examined for helminth parasites following standard parasitological techniques. Results revealed that helminth-infected fish exhibited significantly reduced HSI values (mean 1.95 ± 0.06%) compared to non-infected fish (mean 2.70 ± 0.08%; F = 22.41, p < 0.05). Microscopic examination revealed the damage in hepatic tissues, including necrosis and lipid depletion, correlating with reduced HSI. The study demonstrates that HSI can be a rapid, non-lethal+ indicator of fish health and parasitic impact in aquaculture settings. Regular monitoring of HSI and parasitic loads could aid in developing management practices to improve survival and growth in tilapia culture.
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