RESUMO
Parasites represent a great, unknown component of animal biodiversity. Recent efforts have begun to uncover patterns of infection by helminth parasites in several Neotropical lizards. The present study reports, for the first time, levels of helminth infection in a population of the flat lizard Tropidurus semitaeniatus. One hundred and thirty-nine lizards were examined and evidence of five intestinal helminth species was found, comprising four species of nematodes, one species of cestode and an unidentified encysted larval nematode. The most frequently occurring species was the intestinal nematode Parapharyngodon alvarengai, which did not exhibit differences in prevalence and intensity of infection relative to host sex or age/body size. Furthermore, helminth species richness was not related to host body size.