Rhabdias taquariensis n. sp., a new species of lung parasite of Physalaemus albonotatus from the Brazilian Cerrado.

The diversity of Rhabdias includes 101 species, 71 of which parasitize the lungs of anurans, caudates, gymnophionans, and some occur in reptiles worldwide. Currently, 26 species are found in the Neotropical region, and in Brazil, there are 16 nominal species, a relatively low number considering the high diversity of potential hosts. Here, we describe a new species of Rhabdias found in Physalaemus albonotatus, with morphological and molecular data, as well as phylogenetic analyses using sequences of the mitochondrial gene Cytochrome Oxidase Subunit I (COI). Rhabdias taquariensis n. sp. differs from other known species by a set of morphometric traits and by presenting a well-defined internal shape of the cephalic dilation. Molecular analyses revealed that R. taquariensis n. sp. exhibits a significant divergence of 13.6% in COI compared to the Rhabdias cf. stenocephala species complex. Additionally, phylogenetic reconstructions indicate that the new species represents a distinct lineage, external to a clade formed by species such as Rhabdias fuelleborni, Rhabdias cf. stenocephala, and Rhabdias waiapi. Rhabdias taquariensis n. sp. is the 27th species described in the Neotropical region and the 16th in Brazil, the first description of a species of the genus Rhabdias for Physalaemus albonotatus, and one of the few Rhabdias species described for the Cerrado biome.