Notocotylus chionis (Trematoda: Notocotylidae) and Notocotylus sp. from shorebirds in southern Patagonian wetlands of Argentina: morphological and molecular studies

Abstract

Southernmost South America provides significant wintering habitats for migrant shorebirds, most of which breed in the High Arctic tundra. Helminth species parasitizing these migratory birds have been well studied in North America; however, in South America they are poorly known. As part of an ongoing research on the helminth fauna from Patagonian birds in Argentina, we report Notocotylus chionis and Notocotylus sp. (Trematoda: Notocotylidae) parasitizing three shorebird species, the Nearctic migrants Calidris fuscicollis (WRSA) and Calidris bairdii (BASA) (Scolopacidae), and the Neotropical Charadrius falklandicus (TBPL) (Charadriidae). We provide a new morphological description of N. chionis considering that the previous one reported from the snowy sheathbill on Subantarctic islands are incomplete and based on few specimens. We also provided a morphometric characterization of Notocotylus sp. We obtained molecular data which confirmed the identification of specimens recovered from WRSA and TBPL as N. chionis. Phylogenetic analysis based on 28S ribosomal DNA sequences was performed. The results placed N. chionis close to other Patagonian species native to South America (i.e. N. primulus). Notocotylus chionis was found previously in the snowy sheathbill which inhabits in coasts of southern South America, Antarctic Peninsula and surrounding islands. Present finding in resident birds (TBPL) allows us to hypothesize that N. chionis is a Neotropical species whose life cycle is being completed in southern South America and Subantarctic islands and represents a valuable contribution to the knowledge of parasite diversity in the austral subpolar region of the western hemisphere.