The control of snail intermediate hosts of Schistosoma, the blood fluke, is part of the multi-pronged approach in the control of schistosomiasis. Various molluscicide candidates (synthetic and vegetable) have been documented in literature and these apart from being effective, are also expected to be eco-friendly and not harmful to other non-target organisms in the water bodies where the snails are found. The toxic effect of calcium hypochlorite, a potential molluscicide, on the fresh water fish, Clarias gariepinus was experimentally investigated in the laboratory. Various concentrations of the test chemical viz 6, 8, 10, 15 and 20 mgl^-1 in well water were set up in different tanks into which five (5) fingerlings each of Clarias gariepinus were introduced. For each concentration there were three replicates and control. After the 48 hour assay, the mean LC₅₀ was 12.88mg/l and LC₉₅ was 17.66mg/l. Results showed that the test chemical demonstrated Piscicidal effect at concentrations higher than necessary for the control of water snails as reported elsewhere. The significance of the result as it relates to community water treatment and mollusciciding in schistosomiasis control is discussed.

Keywords: Calcium hypochlorite, Molluscicide, Toxicity, Clarias gariepinus, Schistosomiasis, Control.

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Oniya, M. Oladipo

Department of Biology, Federal University of Technology, PMB 704, Akure, Ondo state, Nigeria