Cosmocerca goroensis n. sp. (Nematoda: Cosmocercidae) from South Africa and its phylogenetic relationships with other cosmocercids based on partial 28S sequences.

Abstract

Nematodes of the genus Cosmocerca are commonly found in various amphibians in South Africa and in most cases are identified as C. ornata. However, after detailed morphological studies and molecular approaches, three new species of the genus were recently described from three different frogs in South Africa. In present study, we describe another new species - Cosmocerca goroensis parasitising the Northern Pygmy Toad Poyntonophrynus fenoulheti in Soutpansberg mountains, Limpopo province, South Africa. The new species is characterised by prominent sex dimorphism, wide lateral alae, numerous somatic papillae in both sexes, and wide triangularly shaped gubernaculum and simple prominent spicules in males. Cosmocerca goroensis n. sp. distinguished from congeners, previously reported in Southern Africa by the shape of the gubernaculum and arrangement of somatic papillae in males. Morphological differences were confirmed by molecular analysis based on fragments of the 28S gene. Phylogenetic analysis based on the 28S gene fragments, including C. goroensis n. sp. and newly obtained sequence of C. ornata from Pelophylax lessonae from Ukraine, supported previously known data of closer relationships between species of Cosmocerca and Aplectana and more distant with Cosmocercoides spp.