The trematodes from South American reptiles are poorly known, with only one life cycle completely characterized. We used molecular and morphological methods to characterize diplostomoid metacercariae found in 29 of 86 pointedbelly frogs, Leptodactylus podicipinus (Cope, 1862) collected in a marsh pond in Selvíria, in the central-west region of Brazil. The metacercariae were identified as Heterodiplostomum lanceolatum Dubois, 1936 (Proterodiplostomidae), a rarely reported species that matures in snakes. In phylogenetic analysis of partial sequences from 28S rDNA, H. lanceolatum fell within a polytomy with the proterodiplostomid Crocodilicola pseudostoma (molecular divergence of 4.1%) and other members of the superfamily Diplostomoidea. Our collections provide insights into the ecology of this parasite, in that infected frogs were smaller than uninfected frogs, and metacercariae were more numerous in the abdominal cavity and hindlimb muscles than in abdominal muscles, which suggests directions for future research on the transmission and pathology of this proterodiplostomid.

Abstract

Neotropical lizards are known to harbour rich nematode parasite faunas; however, knowledge of the diversity and patterns of infection are still lacking for many species. This is true for the genus Tropidurus, in which data on patterns of parasitism are known for only approximately 11 of its 30 species. We show that the nematode fauna associated with a population of Tropidurus montanus is composed of three species of host-generalist parasites with high overall prevalence. Male and female lizards did not differ in infection pattern and there was no relationship between host body size and intensity of infection for the most prevalent parasite species. Nevertheless, overall prevalence changed seasonally, with a higher proportion of parasitized individuals being found in the dry period than in the rainy period. We discuss our findings in the context of diet patterns of T. montanus, which we suggest may explain the similarities in prevalence and intensity of infection between the sexes. In addition, seasonal changes in diet are considered to be related to the observed differences in prevalence between dry and rainy periods.

Brasil es el país con la mayor riqueza de anfibios del mundo con alrededor de 1.136 especies descritas, de las cuales 1.093 son anuros. Sin embargo, los estudios relacionados sobre el conocimiento de la fauna de helmintos asociados son escasos, y representan solo el 8% de los anuros. Este estudio tuvo como objetivo identificar las comunidades de parásitos y sus parámetros parasitarios en dos especies de anfibios: Chiasmocleis albopunctata (Boettger, 1885) y Dendropsophus nanus (Boulenger, 1889) que se encuentran en el este del estado de Mato Grosso do Sul. Los hospedadores fueron recolectados a través de trampas de caídas con cercas de deriva (PTDF) y por el método de búsqueda activa en los sitios de reproducción, sacrificados, y los helmintos fueron removidos e identificados. Se recolectaron un total de 172 anfibios: 70 individuos de C. albopunctata (Boettger, 1885) y 102 individuos de D. nanus (Boulenger, 1889). De este total, 84 fuero n parasitados por al menos un taxón. El número total de helmintos encontrados fue de 675. Aquí informamos diez taxones de helmintos, incluidos dos nuevos registros para la especie hospedadora D. nanus y cinco registros para la especie hospedadora C. albopunctata. Por lo tanto, este estudio representa una contribución importante al conocimiento de la diversidad de parásitos y huéspedes, ya que la cantidad de estudios es insuficiente y no representativa.