pathologic studies on Some mycotic Diseases In Fresh water Fish

Forty Tilapias, 30 Catfish and 30 Common carp were gatheredfrom Dakahlia (El-Manzalah Lake) to study the clinical signs andlesions associated with Mycotic diseases of freshwater fishes duringthe period from September 2000 to September 2001. Isolation andidentification of the fungal causitive agents were done.Clinically, the affected fish showed anorexia, loss of balance,swimming near the surface of water.Macroscopically, yellow ascitec fluid present associated with ascites.Liver was enlarged friable and dark red in color and gall bladder wasdestended. Kidneys were congested. Also, fin necrosis were present, withdestruction of fins, erythema at the base of fins exophthalmia, roughness ofscales and ulceration of skin.Mycological examination revealed the isolation of 593 isolatesrelated to 5 genera of fungal species and 4 genera of yeast.The most predominant fish pathogens were Candida albicans,Aspergillus species and Saprolegnia species and other less important mouldpathogens like Penicillium, Mucor, Fusarium species beside Candidas andRhodotorula, Trichosporon from yeast. These species were isolated withlow prevalence percentage. While Saprolegnia importance come from egginfection as it affect the commerce.The predilection seats and rates of prevalence of different pathogensrevealed that fins and tail are considered primary predilection seatsfollowed by gills then the internal organs.