Evidence for enhanced salinity tolerance of a suspected fungal pathogen of Atlantic menhaden, Brevoortia tyrannus Latrobe

Abstract

Two saprolcgniaccous fungi, one recovered from Atlantic menhaden, Brevoortia tyrannus Latrobe, and the other from fresh water, were eompared for their abilities to withstand salinity stress. Results of stress protein analyses indicated that vegetative mycelium of the isolate from menhaden was better adapted to mcsohaline salinities than the freshwater isolate. Experiments testing the propagative ability of both fungi during salt exposure further suggested that the fungus reeovered from menhaden was more salt tolerant and possibly survives in estuaries beeause of nutrients present in susceptible fish. Implications of the findings relative to the pathogenic potential of fish pathogenic saprolegniaeeous fungi in estuarine water eolumns are discussed.