Haemosiderosis in Platycephalus bassensis and Diodon nicthemerus in south-east Australian coastal waters

Abstract

The degree of haemosiderin deposition in the spleen, liver, and kidney of P. bassensis and D. nicthemerus was compared in specimens from Port Phillip Bay, and Lakes Entrance, Victoria, Bass Strait, and the Derwent estuary, Tasmania. D. nicthemerus displayed extensive visceral haemosiderosis and fatty infiltration of the liver at all sites, apparently as normal conditions. P. bassensis from Port Phillip Bay displayed severe visceral haemosiderosis, whereas specimens from the remaining sites had only low background levels of haemosiderin deposition. It is suggested that high levels of visceral haemosiderin in fish species normally displaying low levels are indicative of a suboptimal health status in fish populations. No infectious cause of the haemosiderosis in Port Phillip Bay fish has been identified, and toxic or pollution-related causes are thus considered likely to be responsible.