Abstract

Fusarium spp. is ubiquitous soil saprophytes, plant pathogens and opportunistic infectious agents of animals and man. During the last two decades these fungi have been recognized as pathogens of aquatic animals. Crustaceans, bony fishes, cartilaginous fishes, crocodilians, pinnipeds and cetaceans represent a diverse sampling of marine animals that have been reported with Fusarium sp. infections.

The species Fusarium solani was responsible for an infection involving an adult scrawled file fish (Aluterus scriplus). The fish was noted as having a swelling in the perianal area and exhibited errant swimming behavior prior to euthanasia. Gross examination revealed a large, pale, protruding lesion caudal to the anus. The tissue was pale yellow, friable and invaded the muscles of the tail. Internal organs appeared normal. Histological examination revealed fungal hyphae located within and between muscle fibers, surrounded by inflammatory cells and necrotic debris. Scar tissue mixed with the hyphae and inflammation was indicative of chronic infection.

Culture of the lesion was incubated on anaerobic blood agar which produced purple colonies with a wooly mycelia. Microscopic evaluation of the colonies revealed sickle-shaped, multiseptate macrocondida indicative of Fusarium spp.

The source of infection in this scrawled file fish has never been identified. The Fusarium organism may have become established secondary to a traumatic event, however, this hypotheses is unproven.

Acknowledgements

We would like to thank the faculty at North Carolina State University-College of Veterinary Medicine, the University of Missouri-College of Veterinary Medicine and Penn State University for their assistance with this project.

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