Control of saprolegniosis in the eel Anguilla australis Richardson, by Aeromonas media strain A199.
The probiotic activity of Aeromonas media strain A199 for the control of saprolegniosis at low water temperatures was trialled in a laboratory-based challenge using the eel, Anguilla australis Richardson. Eels were challenged in the presence of a physiological and physical stress akin to that preceding the winter outbreaks of saprolegniosis in farms. The concentration of Saprolegnia parasitica cysts was 9±1.2 cysts/ml for the initial challenge. Morbidity due to saprolegniosis was low, at 27% in A199-treated tanks, in comparison to the 44% recorded for the non-treated control tanks. The subsequent addition of live A199 cultures to the treatment tanks resulted in the recovery of fish suffering from saprolegniosis (p=0.038), with temperature appearing to be a factor regulating the effect of A199. It was concluded that A199 is a potential agent for the management of winter outbreaks of saprolegniosis in eels.