Gastrointestinal parasites of bottlenose dolphins Tursiops truncatus at the southern extreme of the southwestern Atlantic, with notes on diet composition

ROMERO, MARÍA ALEJANDRA; FERNÁNDEZ, MERCEDES; DANS, SILVANA; GARCÍA, NÉSTOR; GONZÁLEZ, RAÚL; CRESPO, ENRIQUE

DISEASES OF AQUATIC ORGANISMS

INTER-RESEARCH

Lugar: Oldendorf/Luhe; Año: 2014 vol. 108 p. 61 - 70

0177-5103

The gastrointestinal tracts of six bottlenose dolphins (Tursiops truncatus) from Patagonia were surveyed for helmiths and, the diet composition was characterized. All the dolphins were parasitized (6,477 helminths) and seven species were found, including nematodes Anisakis simplex s.1., Pseudoterranova decipiens, acantocephalans Corynosoma cetaceum, C. australe, and digeneans Braunina cordiformis, Pholeter gastrophilus and Synthesium tursionis. Among the gastric helminths, the most prevalent species were C. cetaceum andA. simplex. C. australe and S. tursionis occurred in the intestine with low prevalence. The finding of C. australe and P. decipiens in bottlenose dolphin constitutes new host records. Five stomachs contained food remains (103 preys). The most important prey species were Geotria australis and Stromateus brasiliensis, although although their role in parasite transmission is not clear. At the community level, the gastrointestinal parasite community of T. truncatus was depauperate and exhibited a high overlap with the described community for pelagic dolphins that inhabit Patagonia, suggesting a strong local influence in the shaping the helminth communities. Nevertheless, these observations are in contrast with the notion that oceanic cetaceans have a comparatively poorer helminth fauna than that of neritic species, as are bottlenose dolphins, due to the decreased in likelihood of parasite exchange.