Histopathological effects induced in Mytilus edulis by Mytilicola intestinalis and the histochemistry of the copepod intestinal cells

Abstract

Localised metaplastic changes in the gut epithelial cells of Mytilus edulis were found to be associated with the presence of the parasitic copepod, Mytilicola intestinalis. These changes involved the replacement of the ciliated columnar cells by non-ciliated cuboidal cells. Experimental thermal stress induced a significant increase in the numbers of macrophages in the connective tissues of both infected and uninfected mussels, but there was no evidence of any synergistic effect in infected hosts. A number of lysosomal hydrolases are associated with the gut cells of the parasite where they may be involved in intracellular digestion. It is concluded that Mytilicola intestinalis has no significant effect on the basic cellular functions in Mytilus edulis