Morphological and molecular description of Serpinema yehi n. sp. (Nematoda: Camallanidae), parasite of Rhinoclemmys punctularia (Testudines: Geoemydidae) from Brazilian Amazon

Abstract Serpinema currently comprises 12 valid species of nematode parasites of freshwater turtles, distributed across the Neotropical, Oriental and Palearctic regions. Thus, we describe Serpinema yehi n. sp., a parasite of Rhinoclemmys punctularia from the Brazilian Amazon. Species identification was based on light and scanning electron microscopy, and molecular and phylogenetic analyses were performed using partial sequences of the mitochondrial cytochrome c oxidase subunit I and nuclear 18S genes. Serpinema yehi n. sp. can be distinguished from its congeners by the number of ridges in the buccal capsule, the number and arrangement of caudal papillae, the length and morphology of the right spicule, vulvar lip morphology and the number of mucrons on the female tail. Phylogenetic analyses recovered the new species as closely related to Camallanus , but not nested within the Camallanus spp. clade, thereby supporting the recognition of Serpinema as a valid genus. Serpinema yehi n. sp. represents the second species of the genus described from R. punctularia and the eighth species recorded from Brazil.