Author(s): Nashwa S Elias, Nadia A Abd El Ghany
The effects of Fusarium moniliform infection on Clarias gariepinus fecundity were investigated. Drastic effects were detected in 100% of females and 70% of males of the artificially injected fish with 0.1 ml. of spores suspension contained Fusarium moniliform spores with concentration of 1×10 and the percentage 4 of mortality was 20%. The external clinical signs appeared as severe hemorrhagic patches of the skin, redness around the mouth, erosion of fins and tail, erythematic and ulceration of muscles, ulceration around the site of inoculation, circular black wounds were found on the ventral side with complete loss of coloration. Fungal re-isolations were performed from all females and 70% of males 48 h post injection. Males revealed vacuolation and necrosis of seminferous tubules with high percent of dead sperms, while females copied highly severe drop in the number of matured ova accompanied by atretic follicles. External examinations of some infected ovaries revealed either hemorrhagic patches and asymmetry. Fish fecundity was obviously dropped through gonadal weight (W ), gonadosomatic (I ), in addition to relative and absolute fecundity. Moreover, the total protein and GG liver enzymes of both sexes were markedly decreased. 30% of the injected males showed no changes either externally or internally. Nigella sativa oil at concentration of 0.3ml. / 100 g fish body weight exerted no significant improvement in infected fish fecundity of both sexes. In the same time, Fusarium moniliform was reisolated from a few percent (about 10%) of treated males. On the other hand, fecundity of Allium sativum powder treated males and females at concentration of 30 g / Kg. diet, obviously improved fecundity, but it is still low than that of the control group. It was recommended to use garlic powder in fish diet for prophylaxis rather than for medication against Fusarium infection.