International eel symposium, 2003 - Quebec August 11, 2003
Oral Presentation

The Metazoan Parasites of Eels (Anguilla anguilla) in Ireland: Zoogeographical, Ecological and Fishery Management Perspectives

McCarthy, T.K.* Department of Zoology, National University of Ireland, Galway, Republic of Ireland.
Creed, K. Department of Zoology, National University of Ireland, Galway, Republic of Ireland.
Naughton, O. Department of Zoology, National University of Ireland, Galway, Republic of Ireland.
Cullen, P. Department of Zoology, National University of Ireland, Galway, Republic of Ireland.
Copley, L. Department of Zoology, National University of Ireland, Galway, Republic of Ireland.

Presenter email address: tk.mccarthy AT nuigalway.ie

Abstract Text: Ireland's freshwater fish fauna, limited by geographical isolation following Pleistocene glaciations, has been significantly changed by species introductions. European eel (Anguilla anguilla), an indigenous exploited species, is widely distributed in Ireland and is sometimes the dominant fish in lowland river communities. At least, twenty-seven metazoan species parasitize Irish eels. Some are specialist eel parasites but many utilize a range of fish hosts. Many were accidentally brought to Ireland, during deliberate fish introductions. Changing distributions of preferred intermediate hosts have affected other eel parasites. Vehicles used for commercial transport of eels have been implicated in introduction and spread of potentially pathogenic parasites, including Asian nematode Anquillicola crassus. Parasite assemblages of a series of Irish eel populations have been analysed and individual host characteristics, such as size and diet, were shown to be important at the infra-community level. Likewise, variation in biotic and abiotic features of ecosystems was reflected in composition and structure of eel parasite component communities. Environmental changes, such as eutrophication and species introductions, may be monitored by reference to changing parasite assemblages. Better regulation of species introductions and translocations are needed to protect the ecological integrity of Ireland's freshwater systems and to avoid further economic damage by alien taxa