First published record of the pathogenic monogenean parasite Neobenedenia melleni (Capsalidae) from Australia

The monogenean Neobenedenia melleni (Mac-Callum, 1927) Yamaguti 1963 is a w ell-known and virulent pathogen in culture conditions recorded from the ski n of many teleost fish species worldwide. Until now, N. melleni has not bee n reported from wild or cultured fish in Australian waters, This study docu ments a recent outbreak of N, melleni that occurred on Lates calcarifer (ba rramundi) cultivated in sea cages in Hinchinbrook Channel between Hinchinbr ook Island and mainland Queensland, Australia, which resulted in the loss o f 200 000 fish (50 tonnes), The origin of this outbreak is unclear because N. melleni has not been recorded from any wild host species in Australia an d strict quarantine regulations exclude the possibility of its introduction on imported fish. We propose that N. melleni occurs naturally on wild popu lations of some teleost species in Australian waters and that the few surve ys of wild fish conducted along the east coast have failed to report this s pecies, The possibility that uncharacteristically low water temperatures le d to the outbreak is discussed.