Centrorhynchus nahuelhuapensis n. sp. (Acanthocephala: Centrorhynchidae) from rufous-legged owl (Strix rufipes King) in Patagonia.

Centrorynchus nahuelhuapensis n. sp. is described from the intestine of Strix rufipes， the rufous-legged owl， in Patagonia， Argentina. This species is characterized by the presence of 31-33 hook rows with 16-17 hooks per row， distributed as follows: 5 true hooks， 4 transitional hooks with 4 alate processes， more evident in the first three， 7-8 spiniform hooks， and three cement glands. It differs from most members of the genus by having a filiform body， the arrangement and size of the hooks， the number of cement glands， and egg size. Part of the SSU and LSU genes were sequenced and compared to those in GenBank. Sequences are most similar to other species of Centrorhynchus， supporting their placement within this genus. We present the first molecular study for a species of Centrorhynchus from South America. Additionally， it is the second species of the genus described in Argentina， and the first species of a terrestrial acanthocephalan from a bird in Patagonia.