DAO 47:201-208 (2001)  -  doi:10.3354/dao047201

Gastrointestinal helminths of Commerson¹s dolphins Cephalorhynchus commersonii from central Patagonia and Tierra del Fuego

Bárbara Berón-Vera1,*, Susana Noemí Pedraza1, Juan Antonio Raga2, Alicia Gil de Pertierra3, Enrique Alberto Crespo1, Mariano Koen Alonso1, R. Natalie P. Goodall4

1Laboratorio de Mamíferos Marinos, Centro Nacional Patagónico, CONICET, Blvd. Brown 3600 (9120) and Universidad Nacional de la Patagonia, Blvd. Brown 3700 (9120), Puerto Madryn, Chubut, Argentina
2Departamento de Biología Animal, Instituto Cavanilles de Biodiversidad y Biología Evolutiva, Universitat de Valencia, Dr. Moliner 50, 46100 Burjasot, Valencia, Spain
3Laboratorio de Helmintología, Facultad de Ciencias Exactas y Naturales, UBA, Pabellón II, Ciudad Universitaria (1428), Buenos Aires, Argentina
4Proyecto AMMA, Centro Austral de Investigaciones Científicas (CADIC), Ushuaia (9410), Tierra del Fuego, Argentina

ABSTRACT: The stomachs and intestines of 9 Commerson¹s dolphins incidentally caught in trawl nets in central Patagonia and 23 stranded on beaches in Tierra del Fuego were surveyed for helminth parasites. A total of 267 individuals belonging to 4 species of parasites (1 nematode, 3 digeneans) were found in the dolphins from the first area: Anisakis sp. (larvae type 1 = A. simplex), Braunina cordiformis, Hadwenius sp. and Pholeter gastrophilus. In the Tierra del Fuego dolphins, 142 specimens belonging to 3 species (2 nematodes, 1 digenean, 1 cestode) were found: A. simplex, Hadwenius sp. and Strobilocephalus triangularis. Only 2 of the helminth species were shared in the 2 study areas, A. simplex and Hadwenius sp., and both were more common in central Patagonia. Among the species, A. simplex was most prevalent and abundant in both study areas. In Tierra del Fuego, adults of A. simplex appeared in only 1 host. Hadwenius sp., P. gastrophilus and S. triangularis are new host records for Commerson¹s dolphin. Species diversity and species richness were low in both study areas. Helminth communities were more diverse in central Patagonia (t = 1.97, df = 258, p < 0.05) and species richness was higher in central Patagonia (S = 4). No differences in diversity were observed between females and males of central Patagonia (t = 1.97, df = 139, p < 0.05) and between females of central Patagonia and Tierra del Fuego. The results may suggest some differences in habitat use, diet and sex between Commerson¹s dolphin populations in the 2 study areas.


KEY WORDS: Commerson¹s dolphin · Cephalorhynchus commersonii · Gastrointestinal parasites · Hadwenius sp. · Pholeter gastrophilus · Strobilocephalus triangularis · Central Patagonia · Tierra del Fuego


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