Gastrointestinal nematodes of the lizard Tropidurus hispidus (Squamata: Tropiduridae) from a semi-arid region of north-eastern Brazil

The tropidurid lizard Tropidurus hispidus has a wide distribution in South America. However, knowledge about its helminth fauna is patchy and has been reported for only a few localities along its range of distribution. This study presents data on helminth fauna composition and parameters of infection for a population of T. hispidus from an area within the Brazilian Caatinga biome (semi-arid physiognomy). We found five nematode species within the gastrointestinal tract of lizards: Parapharyngodon sceleratus (Pharyngodonidae); Physaloptera lutzi, Physaloptera retusa and Physalopteroides venancioi (Physalopteridae); and Strongyluris oscari (Heterakidae). The overall prevalence was 84.2% and the mean intensity of infection was 8.5 +/- 1.1. The body size of adult male lizards influenced positively the intensity of infection. The infracommunities of nematodes presented an intermediate aggregated distribution (discrepancy index; D = 0.519) and a depauperate nematode fauna. The presence of generalist parasite species has contributed to an increase in the overall richness of the component community. This sampled host population presented the highest prevalence of parasites compared with other studies on T. hispidus, but their relatively low richness can be related to the disturbed environment of the study area.