The occurrence ofPodocotyle atomon(Rud., 1802)(Digenea),Bothriocephalus scorpii(Müller, 1776) (Cestoda),Contracaecum clavatum(Rud., 1809) (Nematoda) andEchinorhynchus gadiZoega, in Müller, 1776 (Acanthocephala) in the five-bearded rockling,Onos mustelus(L.)

Abstract

Summary The variation in the incidence and intensity of infestation of the five-bearded rockling, Onos mustelus (L.) with Podocotyle atomon, Bothriocephalus scorpii, Contracaecum clavatum and Echinorhynchus gadi has been studied for a period of one year, on a shore at Mumbles Head, Swansea. There is a general increase in the incidence and intensity of infestation by P. atomon and C. clavatum with increase in the length (age) of the host. With E. gadi and B. scorpii, however, infestation decreases in the larger fish. The seasonal variations in the incidence and intensity of infestation with these parasites are influenced by tidal fluctuations, temperature and by the feeding habits and breeding cycle of the fish. The frequency distribution of parasite specimens is also described and discussed.