Branchiomyces-like infection in a cultured tilapia (Oreochromis hybrid, Cichlidae)

Abstract

A Branchiomyces-like fungus was identified from histologically examined gills of juvenile red tilapia Oreochromis niloticus x O. mossambicus and green tilapia O. niloticus x O. aureus obtained from intensive fish farms in Israel. Hyphae embedded in the gill tissue contained undivided and sporulating stages. In one instance infection appeared to be subclinical, limited to one or a few loci in the gill filament and causing only localized tissue damage. In the second case, infection, which was severe and caused extensive tissue damage, was identified in fish from a stock suffering massive mortality which resulted in the loss of 85 % of the pond fish.