Nyctiphanes couchii as intermediate host for the acanthocephalan Bolbosoma balaenae in temperate waters of the NE Atlantic

Abstract

Cystacanths of the acanthocephalan Bolbosoma balaenae (Gmelin, 1790) were found mencapsulated in the cephalothorax of the euphausiid Nyctiphanes couchii (Bell, 1853) from temperate mwaters in the NE Atlantic Ocean. Euphausiids were caught in locations outside the Ría de mVigo in Galicia, NW Spain, and prevalence of infection was up to 0.1%. The parasite was identified mby morphological characters. Cystacanths were 8.09 ± 2.25 mm total length (mean ± SD) and mhad proboscises that consisted of 22 to 24 longitudinal rows of hooks, each of which had 8 or 9 mhooks per row including 2 or 3 rootless ones in the proboscis base and 1 field of small hooks in the mprebulbar part. Phylogenetic analyses of 18S rDNA and cytocrome c oxidase subunit I revealed a mclose relationship with other taxa of the family Polymorphidae (Meyer, 1931). The results extend mnorthwards ot the known distribution of B. balaenae. Taxonomic affiliation of parasites and mtrophic ecology in the sampling area suggest that N. couchii is the intermediate host for B. balenae, mand we suggest that the whales Balaenoptera physalus (Linnaeus, 1758) and B. acutorostrata m(Lacepède, 1804) are its definitive hosts. This life cycle is probably completed with or without mparatenic hosts. m m. © Inter-Research 2012.