P-141
Acute Loss of European Silver Eel Fitness By Introduced (vs native) Parasitic Helminths Threatening Spawning Success

Monday, August 18, 2014
Exhibit Hall 400AB (Centre des congrès de Québec // Québec City Convention Centre)
Claudia Gérard , UMR Ecobio, Université de Rennes 1, Rennes, France
Thomas Trancart , Station Marine de Dinard, Muséum National d'Histoire Naturelle, Dinard, France
Elsa Amilhat , Centre de Formation et de Recherche sur les Environnements Méditerranéens, Université de Perpignan Via Domitia, Perpignan, France
Elisabeth Faliex , Centre de Formation et de Recherche sur les Environnements Méditerranéens, Université de Perpignan Via Domitia, Perpignan, France
Laure Virag , Station Marine de Dinard, Muséum National d'Histoire Naturelle, Dinard, France
Eric Feunteun , Station Marine de Dinard, Muséum National d'Histoire Naturelle, Dinard, France
Anthony Acou , Service des Stations Marines, Station Marine de Dinard, Muséum National d'Histoire Naturelle, Dinard, France
Helminth parasites were studied in 149 silver eels from five sites in northern Europe. In total, 88% were infected by 12 species including Monogena, Cestoda, Nematoda, and Acanthocephala. Anguillicoloides crassus was most common (56%), then Acanthocephalus clavula (30%) and Pseudodactylogyrus spp. (17%). The body condition (BC) was negatively influenced by the abundance of the introduced Pseudodactylogyrus spp. but not by the other parasite taxa. However, the introduced A. crassus was considered as a severe pathogen based on previous data, whereas the native A. clavula was supposed to have limited impact. Eels from Stockholm Archipelago (Sweden) were the less parasitized (30% vs ≥ 90% for other sites) with no parasites in gills. Burrishoole (Ireland) differed by absence of A. crassus and high prevalence of A. clavula (84%) but without consequences on BC. Gudenaa (Denmark), Corrib (Ireland) and Frémur (France) were close due to high prevalence of A. crassus (≥ 89%). Gudenaa and Corrib were the most similar because Pseudodactylogyrus spp. was also highly prevalent (≥ 60%) whereas absent in Frémur. Our results suggest that introduced parasites may threaten the spawning success of migrant silver eels from Gudenaa, Corrib and Frémur, but not of those from Stockholm Archipelago and Burrishoole.