A new species of the genus Stephanoprora Odhner, 1902 [Digenea, Echinostomatidae] from Argentina

Stephanoprora podicipei sp. n. parasite of great grebe Podiceps major Boddaert, 1785 (Aves, Podicipedidae) from Mar Chiquita coastal lagoon (Buenos Aires, Argentina) is described and illustrated. The new species presents common features with S. conciliata Dietz, 1909; S. manei Holcman-Spector et Olagüe, 1986; S. dogieli Holcman-Spector et Olagüe, 1989 and S. uruguayense Holcman-Spector et Olagüe, 1989. S. podicipei sp. n. can be clearly distinguished from these species, principally, by the smaller size of its body, peristomic disk, testes, ovary and by its shorter oesophagus and uterus. S. podicipei also differs from S. argentiniensis Sutton et al., 1982, the other species of this genus parasitizing Podiceps major in Argentina, in the number of spines of the peristomic disk (22 vs. 20), in its smaller body, peristomic disk and testes; in its larger acetabulum and eggs, in the shape of the testes and in its vitellaria extending to the middle of the anterior testis.