Influence of physicochemical parameters on parasite prevalence and diversity in selected fish species of river Taraba, Nigeria

This study investigates the influence of physicochemical parameters on parasite prevalence and diversity in selected fish species (Oreochromis niloticus, Clarias gariepinus, Synodontis clarias, and Synodontis nigrita) from River Taraba, Nigeria. The study was carried out for an 18 months’ period (November 2021 to April 2023) and a total of 420 fish specimens were used for the studies. Six classes of parasites, including parasitic crustaceans, monogenean trematodes, digenean trematodes, nematodes, ciliates, and dinoflagellates, were identified, with an overall parasite prevalence of 14.527%. Water quality parameters, including dissolved oxygen (DO), phosphate (PO₄³⁻), nitrate (NO₃⁻), temperature, pH, transparency, and conductivity, were analyzed in relation to parasitic infections in fish. The results showed a strong negative correlation between DO and parasite prevalence (r = -0.994, p = 0.006), suggesting that higher oxygen levels reduce parasite occurrence. Additionally, phosphate exhibited a very strong positive correlation with parasite prevalence (r = 0.970, p = 0.030), indicating that increased nutrient levels may enhance parasitic infestations. Temperature and transparency showed moderate to strong positive correlations with parasite prevalence but were not statistically significant. Nitrate, pH, and conductivity demonstrated weak to moderate correlations, suggesting minimal influence on parasite distribution. The study therefore recommends need for effective water resource management to mitigate parasitic infections.