6533b835fe1ef96bd129e939

RESEARCH PRODUCT

GASTROINTESTINAL HELMINTHS OF THE DUSKY DOLPHIN, LAGENORHYNCHUS OBSCURUS (GRAY, 1828), OFF PATAGONIA, IN THE SOUTHWESTERN ATLANTIC

Susana N. PedrazaSilvana Laura DansLaura M. ReyesJuan Antonio RagaEnrique Alberto Crespo

subject

biologyEcologyAnisakis simplexRare speciesSpecies distributionCetaceaZoologyAquatic Sciencebiology.organism_classificationLagenorhynchus acutusHelminthsDusky dolphinLagenorhynchushuman activitiesEcology Evolution Behavior and Systematics

description

The stomachs and intestines of 23 dusky dolphins incidentally caught in a trawl fishery off Patagonia were surveyed for helminths. All the dolphins were parasitized, with a total of 3,936 helminth individuals. Only five species occurred, of which three were common (prevalence ± 10%): Anisakis simplex, Braunina cordiformis and Hadwenius sp. A. simplex was present in all the dolphins and showed the highest abundance and mean intensity (104.9 individuals/infected host). B. cordiformis was next most common (87%), and Hadwenius sp. third (52.2%). A. simplex was found mostly in the stomach (94.8%), B. cordiformis in the duodenal ampulla (51.4%), and Hadwenius sp. in the stomach (64.5%). The rare species Corynosoma australe (immature specimens) and Pholeter gastrophilus occurred in the stomach. A. simplex and B. cordiformis showed a clumped distribution along the intestine. Brillouin's diversity and evenness indices for the intestinal helminth community were 0.329 and 0.393, respectively. The diversity values and the number of parasite species were within the range for other small cetaceans.

yearjournalcountryeditionlanguage
1999-07-01Marine Mammal Science
https://doi.org/10.1111/j.1748-7692.1999.tb00834.x