Intestinal helminths from three species of pinnipeds from the Patagonian coasts in Argentina.

HERNÁNDEZ-ORTS, J.S; F.E. MONTERO; GARCIA, N.A.; J.A. RAGA; CRESPO, E.A; F.J. AZNAR

Setubal

Congreso; 27th. ANNUAL CONFERENCE OF THE EUROPEAN CETACEAN SOCIETY; 2013

We report on the intestinal helminth fauna of 56 South American sea lions, Otaria flavescens, 5 South American fur seal Arctocephalus australis and 1 Southern elephant seal Mirounga leonina from the Patagonian coast in Argentina. A total of 97,325 helminth specimens were collected from sea lions. Gravid individuals were represented by 6 species of parasites: 1 cestode Diphyllobothrium spp. (prevalence 26.8%; mean intensity: 3.4); the acanthocephalan Corynosoma australe (100%; 1,589); the nematodes Uncinaria hamiltoni (3.6%; 38.0), Contracaecum ogmorhini s.s. (62.5%; 13.3) and Pseudoterranova cattani (66.1%; 14.8) and the digenean Ascocotyle (Ascocotyle) patagoniensis (from 2 hosts; infection parameters could not be determined reliably). Immature specimens of the acanthocephalans Corynosoma cetaceum (8.9%; 2.4), Profillicollis chasmagnathi (0.2%; 1.0) and Andracantha sp. (0.2%; 1.0), and L3 larvae of the nematodes Anisakis sp. (28.6%; 2.3) and Contracaecum sp. (69.9%; 65.5) were also collected. From fur seals, a total of 1,516 helminth specimens were collected. Gravid individuals were represented by 3 species of parasites namely, Diphyllobothrium spp. (20%; 2), C. ogmorhini s.s. (20%; 25) and C. australe (80%; 349.5). In addition, larvae of Contracaecum sp. (20%; 72) and P. cattani (20%; 2), juveniles of C. cetaceum (40%; 5) and immature specimens of a Tetrabothriidae cestode (20%; 7) were also collected. From the elephant seal, gravid specimens of the acanthocephalan Corynosoma bullosum (2 specimens) and Pseudoterranova sp. (1 specimen) were collected. Sea lions and furs seals harbour the intestinal helminth communities that could be predicted for otariids, i.e. the combination of species of the genera Corynosoma, Diphyllobothrium, Pseudoterranova, Contracaecum and, in pups, Uncinaria; and are apparently unsuitable hosts for five parasite taxa. Corynosoma bullosum is restricted to elephant seals, a species that forages at deep waters near the continental slope, whereas the 2 otariids species forage in shallower waters at the continental shelf.