Intestinal helminths from the South American sea lion Otaria flavescens, from North Patagonia, Argentina.

HERNÁNDEZ-ORTS, J.S., F.E. MONTERO, M.S. LEONARDI, J.A. RAGA, F.J. AZNAR & E.A. CRESPO

Anchorage, Alaska

Congreso; 86th ANNUAL MEETING OF THE AMERICAN SOCIETY OF PARASITOLOGISTS; 2011

AMERICAN SOCIETY OF PARASITOLOGISTS

In this study we report on the intestinal helminth fauna of 56 South American sea lions, Otaria byronia (27 females and 29 males) stranded along the North Patagonian coast (Argentina). A total of 12 species was found. The following species had gravid individuals: the cestode Diphyllobothrium scoticum (prevalence [95% C.I.]: 28.6% [17.2-42.2]; mean intensity [95% C.I.]: 3.38 [1.81-7.88]); the acanthocephalan Corynosoma australe (98.2% [90.4-99.9]; 1562.8 [1153.8-2207.3]); the nematodes Uncinaria hamiltoni (5.4% [1.1-14.9]; 25.67 [1.0-46.0]), Contracaecum ogmorhini (62.5% [48.5-75.0]; 13.29 [9.37-19.69]) and Pseudoterranova cattani (64.3% [50.3-76.7]; 15.22 [5.58-51.28]) and the digeneans Synthesium sp. (n=1) and Ascocotyle (Phagicola) sp. (from 2 hosts; infection parameters could not be determined reliably). We also found immature specimens of the acanthocephalans Corynosoma cetaceum (n=7), Profillicollis sp. (n=1) and Andracantha sp. (n=1); L3 larvae of the nematodes Anisakis sp. (26% [15.8-40.3]; 2.4 [1.5-3.9]) and Contracaecum sp. (67.9% [54.0-79.7]; 67.1 [33.0-172.5]). These results suggest that South American sea lions harbour the intestinal helminth fauna that could be predicted for a pinniped (i.e., the combination of species of Corynosoma, Diphyllobothrium and Heterophyidae), except for the presence of Synthesium sp., which is a typical parasite from cetaceans. In addition, sea lions would act as an ecological ?sink? for as many as 5 parasite species from sympatric fish-eating cetaceans (C. cetaceum and Anisakis sp.) and birds (Profillicollis sp., Andracantha sp. and Contracaecum sp.). J.S.H.O. benefits from a PhD student grant of the CONACyT, Mexican Government. Funded by BBVA project no. BIOCON 04 and CGL2007-63221 from the MEC of Spain.