Thorny-headed worms (Acanthocephala) of the Patagonian blennie Eleginops maclovinus (Cuvier) from northern Patagonia, Argentina.

We report the fauna of the Acanthocephala of 120 Patagonian blennies Eleginops maclovinus (Cuvier) from northern Patagonia, Argentina. A total of 535 acanthocephalans belonging to five species were collected and identified using light microscopy. Juvenile and adult forms were only observed for Hypoechinorhynchus magellanicus Szidat, 1950 (Arhythmacanthidae). Juvenile forms of Corynosoma australe Johnston, 1937, Corynosoma cetaceum Johnston et Best, 1942 and Corynosoma shackletoni Zdzitowiecki, 1978 (Polymorphidae) were found encapsulated in the mesenteries. Juveniles of Profilicollis chasmagnathi (Holcman-Spector, Mañé-Garzón et Dei-Cas, 1977) (Polymorphidae) were found free in the intestines of the fish. Hypoechinorhynchus magellanicus was the most abundant acanthocephalan in our study, accounting for 48.4% of all specimens collected, followed by C. australe (33.5%). The Patagonian blennie represents a new host record for four species (C. australe, C. cetaceum, C. shackletoni and P. chasmagnathi). The northern Patagonia in Argentina is a novel locality record for C. shackletoni. This survey improves our knowledge of life cycles and geographical distribution of zoonotic marine acanthocephalans with potential risk to humans and companion animals.