Experimental transmission and pathogenicity of some zoosporic fungi to Tilapia fish.

Seventeen fungal species belong to sex genera were recovered from the four organs of Tilapia fish and the most common were Saprolegnia ferax, S. diclina, Achlya dubia, A. americana, A. racemosa and A. flagellata, Dictyuchus sterile, Pythium undulatum and Aphanomyces sp. Severe infection followed by death of all fish was incited by S. parasitica and S. ferax through experiment I. 30-70% of T. nilotica and T. galileae were killed through experiment II by S. parasitica and S. ferax. T. galileae was more susceptible to fungal infection than T. nilotica.