studies on diseases affecting the skin in some nile fishes

The present study dealt with four major aspects, thefirst one was incidence and classification of skin lesionsoccurring in fresh waier fish from various sources.(Natural resources and artificial aquaculture breedingponds, which includes age, sex and species susceptibili~las well as seasonal influences. The second was the etiolo-gical agents (bacterial, fungal and parasitic) involved inexamined cases. The third aspect was concerned withexperimental infection of the most bacterial isolates inumout catfish to study the pathogenicity, degree of viru-lence as well as the effect of the temperature on the viru-lence of pathogenic bacteria (Aeromonas hyDROPhila andPseudomonas fluorescence) with reporting the clinic~~dhistopathological pictures produced by such microorganisms.The fourth aspect was the treatment of experimentally in-fected fish, in vitro by the sensitivity test and in vivoan infected fish kept in various aquarial conditions