A New Species of Sprentascaris (Nematoda: Raphidascarididae) in Hypostomus commersoni (Pisces: Loricariidae) from Argentina.

Abstract

To report a new species: Sprentascaris pampayensis, a Raphidascarididae parasite from the Neotropical region. During a parasitological survey, specimens were collected of a new species of Sprentascaris from Hypostomus commersoni Valenciennes from urban lakes in Santa Fe City, Santa Fe Province, in the Pampean region of Argentina. Morphological and morphometric descriptions, and molecular analyses were performed. The new species, S. pampayensis n. sp., is characterized by having slightly extended lateral wings in both sexes, oral structure with three well-developed lips with double papillae, ventrolateral lips with an amphidial pore. Triangular buccal opening with three well-developed lips with flattened extensions at their bases, which end in a pointed manner towards the back. Males have 17 pairs of preanal papillae, 1 pair of adanal papillae, 3 pairs of postanal papillae and 1odd median postanal papilla located between the first and second pairs, unusual shape of caudal papillae with the central tubular part conspicuously elevated. Females have pre-equatorial vulva, smooth-shelled eggs, and mature embryonated eggs. Sprentascaris pampayensis n. sp. differs morphologically and genetically from S. manherti Petter and Cassone, 1984, S. lanfrediae Melo, Santos, Giese, Santos and Santos, 2011 and S. andersoni Malta, Paiva, Elisei, Tavares and Pereira, 2018. Morphological and morphometric comparison also distinguishes it from S. pimelodi Petter and Cassone, 1984, S. hypostomi Petter and Cassone, 1984, S. marano Ramallo, 2009, and S. saltaensis Ailán-Choke, Ramallo and Davies, 2017. Sprentascaris pampayensis n. sp. is a new parasitic nematode of Hypostomus commersoni.