The adhesive mechanisms of monogenetic trematodes: the attachment of Plectanocotyle gurnardi (v. Ben. & Hesse) to the gills of Trigla

Abstract

Little is known of the mechanisms whereby trematode parasites of fish gills attach themselves to their hosts. The adhesive apparatus consists of a posterior set of suckers or clamps supported by skeletal bars (sclerites) whose arrangement varies considerably in the different species. Yet though the pattern of these sclerites forms the main basis for the classification of the 200 or so species of the Diclidophoroidea into its six families, the only attempts to describe the mechanism of attachment of these parasites to their hosts appear to be those of Cerfontaine (1896), who described the attachment of Diclidophora denticulata to the gills of Gadus viretis, and of Sproston (1945a) and Llewellyn (1956a), both of whom described the attachment of Kuhnia scombri to the gills of Scomber scombrus. In the present paper the mechanism by which Plectanocotyle gurnardi (v. Ben. & Hesse) adheres to its hosts Trigla cuculus L., and T. lineata Gmelin will be described.