The effect of certain antiprotozoal drugs on the fresh water; catfish and their role in fish production

The purpose of this study was toinvestigate the efficacy of certainantiprotozoal drugs includingformalin , malachite green , their combinationand metronidazole on external protozoal infestation with Trichodina , Myxobolus and Henneguya in fresh water catfish.Our findings revealed a high efficacy of formalin , malachite greentheir combination and metronidazole in the treatment of fish ectoprtozoalinfections by Trichodina , Myxobolus and Henneguya .Formalin was effectiveagainst Trichodina in a percentage of 80% , 100% for Myxobolus and 75%for Henneguya . Malachite green was effective against Trichodina III apercentage of 90% , 66% for Myxobolus and 50% for Henneguya . Metronidzaol and combination of formalin with malachite green were effective in a percentage of 100% against the same three genera of protozoa. Studies were directed for detecting the mechanism