Notocotylus primulus n. sp. (Trematoda: Notocotylidae) from the crested duck Lophonetta specularioides (Aves, Anatidae) from Patagonian coast, southwestern Atlantic Ocean.

Species in the genus Notocotylus (Trematoda, Notocotylidae) are cosmopolitan parasites of mainly aquatic birds and, to a lesser extent, mammals. In this paper we describe Notocotylus primulus n. sp. parasitizing the Crested Duck, Lophonetta specularioides , from the Patagonian coast, southwestern Atlantic Ocean, based on morphological and molecular data. The new species could be distinguished from its congeners by the combination of several features; among them, the position of the genital pore that is prebifurcal and located close to the posterior margin of the oral sucker, a greater number of both ventral papillae and uterine loops, and a large cirrus sac. Molecular results of the ITS2 sequence support the location of this new species in the genus Notocotylus due to a close relationship with Notocotylus malhamensis (the lower genetic distance of the ITS2 sequences). Unlabelled Image • Notocotylus primulus n. sp. is described from Lophonetta specularioides from Argentina. • The new species is morphologically and genetically characterized • It is the first record of a trematode parasite in the endemic Crested Duck. [ABSTRACT FROM AUTHOR]