The distribution of metacercariae of Maritrema arenaria (Digenea: Microphallidae) in the barnacle Balanus balanoides at three sites on the east coast of Northern Ireland

Abstract

Overall incidence of metacercariae of Maritrema arenaria differed substantially at each of the three sites investigated. In each case, however, numbers were higher than those previously observed in the British Isles. Results indicate that gulls rather than waders are the more important final hosts of this parasite in the areas investigated. At one site where a more detailed survey was carried out metacercariae were more abundant on the upper half of the shore and they displayed a marked preference for barnacles on living Littorina littorea shells as compared to barnacles on rocks. Evidence would suggest that the two most likely molluscan hosts of this trematode are Littorina saxatilis and Nucella lapillus.