Light microscopic study of the pathology of a species of didymozoan, Nematobothriinae gen. sp. from the gills of slimy mackerel Scomber australasicus

Abstract

Slimy mackerel Scomber australasjcus from Eden, New South Wales, Australia, Miere examined for didymozoan parasites. Flve species of didymozoans were recorded Four species were encapsulated in the main gills and one was found in the fins, finlets, operculum, some skull bones and around the eyes. In order to understand the pathology, primary gill lamellae infected by one species of didymozoan were compared to uninfected gill Idnwllae. The parasites occupied the space between the basement membrane of the primary epithel~uin and the efferent artery of the primarv glll lamellae The response of the host cons~sted mainly In a stretching of the lateral epithelium and the fornlation of a layer of columnar eplthelial cells.