Ecological factors influencing the composition of the parasite fauna of the European eel, Anguilla anguilla (L.), in Ireland

Abstract

The parasites of 121 eels from three contrasting sites in the Corrib catchment area, western Ireland, were investigated. Thirteen species, Ergusilus gibbus, Diplosromun gasrerosrei. Diplosrornrtnr spurhaceum. Sphaerosroma branrae. Borhrocephalus claviceps. Proreocephalus mrrc~rocepholus. Cavrullunus lacusiris, Cucullanus rruriae, Parayuimperia renerrima, Ruphidascaris acus. Acunrhocephalus clavulu, Aconlhocephulus lucii and Pomphorhvnchus luevis, were recorded. Two species, P. macrocephalus and P . renerrima, have not previously been reported from Ireland. Microhabitat preferences of the parasites were noted. Variations in the occurrence and intensities of the parasites observed were analyzed in relation to sampling period. host habitat and characteristics of the eel populations studied. A variety of factors were shown to be of importance, including composition of the fish communities and distributional patterns of intermediate hosts and piscivorous birds. Differences were noted in the parasitocoenoses of eels in still and running water sites. The occurrence and intensities of infection of several parasite species were shown to be related to age and size of host: the occurrence of B. cluviceps. C . fruiiae, P. ienerrima and R. acus was shown to be related to either age or size ofeels, which is accounted for by the fact that eels become increasingly piscivorous with age and increasing size. Little evidence of interspecific interactions was noted.

Influence of host sex and age on infracommunities of metazoan parasites ofProchilodus lineatus(Valenciennes, 1836) (Prochilodontidae) of the Upper Paraná River floodplain, Brazil

“…Therefore, the study of age, as well as length, has become an important tool to understand the relationships between parasites and their hosts. Lawrence (1970), Muzzall (1980 and Conneely & McCarthy (1986) observed that in addition to age, host sex and flood period also influenced parasite abundance. The action of these factors on the parasite fauna is considerable, mainly for those that have several organisms as intermediate hosts.…”

Salinity dependence of parasite infestation in the European eel Anguilla anguilla in northern Germany

“…Conneely and McCarthy, 1986;Køie, 1988a;Kennedy, 1993Kennedy, , 1997Schabuss et al, 1997;Kennedy et al, 1998;Sures et al, 1999;Di Cave et al, 2001;Aguilar et al, 2005;Kristmundsson and Helgason, 2007). Investigations on the parasite fauna of European eels in marine habitats (Outeiral et al, 2001(Outeiral et al, , 2002Kristmundsson and Helgason, 2007) are scarce.…”

Interspecific interactions between Acanthocephala in the intestine of brown trout: are they more frequent in Ireland?

“…Firstly, there is evidence to suggest that Acanthocephala are more likely than other groups of helminths to exhibit negative interactions with their own and other species, under both field (Chappell, 1969 ;Grey & Hayunga, 1980 ;Kennedy, 1992 ;Vidal-Martinez & Kennedy, 2000) and experimental conditions (Holmes, 1961Holland, 1984Holland, , 1987Bates & Kennedy, 1990, 1991. Secondly, the likelihood of these interactions is increased in Ireland because of the absence of certain definitive hosts (Lyndon & Kennedy, 2001) and the fact that concurrent infections by 2 or more species of Acanthocephala are more commonly observed in aquatic hosts including fish (Kane, 1966 ;Kennedy, 1966 ;Conneely & McCarthy, 1984, 1986Holland & Kennedy, 1998). For example, Kennedy & Moriarty (1987) observed stable populations of Acanthocephalus lucii and Acanthocephalus anguillae in eels over a 3-year period in Lough Derg.…”