Intestinal helminth fauna of the South American sea lion Otaria flavescens and fur seal Arctocephalus australis from northern Patagonia, Argentina

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

J. HELMINTHOL.

Cambridge University Press

Lugar: Cambridge; Año: 2012 vol. 87 p. 336 - 347

0022-149X

We report on the intestinal helminth fauna of 56 South American sea lions,Otaria flavescens, and 5 South American fur seals, Arctocephalus australis, fromnorthern Patagonia, Argentina. A total of 97,325 helminth specimens werecollected from sea lions. Gravid individuals were represented by 6 species ofparasites: 1 digenean (Ascocotyle (Ascocotyle) patagoniensis), 1 cestode (Diphyllo- bothrium spp.), 3 nematodes (Uncinaria hamiltoni, Contracaecum ogmorhini s.s.,Pseudoterranova cattani) and 1 acanthocephalan (Corynosoma australe). In addition,third-stage larvae of 2 nematodes (Contracaecum sp. and Anisakis sp. type I) and 3 juvenile acanthocephalans (Andracantha sp., Profilicollis chasmagnathi andCorynosoma cetaceum) were also collected. Andracantha sp., C. ogmorhini s.s. andP. chasmagnathi represent new host records. A total of 1516 helminth specimenswere collected from fur seals. Gravid individuals were represented by 3 species of parasites, namely, Diphyllobothrium spp., C. ogmorhini s.s. and C. australe. In addition, larvae of Contracaecum sp. and P. cattani, juveniles of C. cetaceum and immature cestodes (Tetrabothriidae gen. sp.) were also collected. Corynosomaaustrale was the most prevalent and abundant parasite in both hosts, accounting for .90% of all specimens. Sea lions and furs seals from northern Patagonia 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. Additionally, both species of otariid are apparently unsuitable hosts (i.e. non-hosts) for as many as five parasite taxa. The inclusion or exclusion of these species affects estimation ofspecies richness at both component community (11 versus 6 species in sea lions; 7 versus 3 species in fur seals) and infracommunity (mean: 3.1 versus 2.6 in sea lions; 2.2 versus 1.7 species) levels. Information about the reproductive status of helminth species is often lacking in parasitological surveys on otariids and other marine vertebrates, but it is of significance to improve precision in parascript studies or ecological meta-analyses.