Descrição de novas espécies de helmintos (Nematoda) endoparasitas de anfíbios anuros da Amazônia Meridional

Abstract

Amphibians were the first vertebrates to colonize the terrestrial environment, having intermediate characteristics between fish and terrestrial amniotics. These animals are hosts of various endo and ectoparasites. However, the study of parasites in these organisms is still incipient, since almost 92% of the species do not have any type of study. In the present work, the parasites of two species of amphibians collected in the Southern Amazon, State of Mato Grosso, Brazil, were analyzed. For the analysis of morphological and morphometric characteristics, light microscopy and scanning electron were used, resulting in the description of two new species: Cosmocercoides meridionalis n. sp. (Nematoda: Cosmocercidae) based on specimens of the large and small intestine of Osteocephalus taurinus Steindachner, 1862. This new species differs from its congeners by combining the following characters: absence of gubernaculum, total length of the female (twice the size of the male) and the presence of 13 pairs of rosettes with a unique arrangement and distribution pattern, with 11 ventral pre-cloacal pairs, an ad-cloacal pair and a post-cloacal pair. Schrakiana peugeoti n. sp. (Nematoda: Atractidae) parasite of the large intestine of Leptodactylus mystaceus (Spix, 1824). Schrankiana peugeoti n. sp. is distinguished from all similar species by not having a lateral wing, female and male body larger than most species of the genus and by the disposition of post-cloacal papillae being the only species to have two pairs of sub-dorsal papillae. The present study expands the information on the diversity of species of amphibian parasitic nematodes.