Physaloptera bainae n. sp. (Nematoda: Physalopteridae) parasitic in Salvator merianae (Squamata: Teiidae), with a key to Physaloptera species parasitizing reptiles from Brazil.

Physaloptera bainae n. sp. (Nematoda: Physalopteridae) from stomach of the large "tegú" lizard Salvator merianae (Squamata: Teiidae), collected in an ecological park that is part of the Atlantic Rainforest biome in Juiz de Fora, Minas Gerais, Brazil, is described. The new species which has females with didelphic uterus, is the only species of the genus exhibiting external teeth in the form of 4 spines that are organized in a cross-shaped pattern at the anterior apical end, with 2 minute adcloacal papillae on the anterior part of cloacal aperture in males and a large cuticular expansion at the anterior end of females. Moreover, P. bainae n. sp. can be differentiated from the other congeners by the combination of other features, e.g., number (23) and pattern of caudal papillae, spicule size (left 554-600; right 589-617) and vulval position (on the first third of body), and because the specimens are particularly large and robust. Physaloptera monodens is considered a junior synonym of P. obtusissima. In addition, a key to Physaloptera species parasitizing reptiles from Brazil is provided.