Helminth’s assemblage of trachemys dorbigni (Testudines: Emydidae) in southern Brazil: Implications of anthropogenic environments and host’s genders

Abstract

The assemblage of helminths of Trachemys dorbigni was analyzed according two environments (rural and urban) and according to host’s gender. Thus, the helminths found were: Spiroxys contortus (Rudolphi, 1819), Falcaustra affinis (Leidy, 1856), Camallanus emydidius Mascarenhas & Müller, 2017, Dioctophyme renale (Goeze, 1782) (larvae), Eustrongylides sp. (larvae) (Nematoda), Telorchis corti (Stunkard, 1915), Telorchis achavali Mañé-Garzón & Holcman-Spector, 1973, Telorchis spp. (Digenea), Polystomoides rohdei Mañé-Garzón & Holcman-Spector,1968 and Neopolystoma sp. (Monogenoidea). Parasitological indices suggests that S. contortus, F. affinis, C. emydidius, T. corti and P. rohdei are species common in helminth assemblage of T. dorbigni in southern Brazil. Infection by Dioctophyme renale is typical of the urban area and suggest relation with eutrophication process and feedback of parasitic cycle in the freshwater urban environment. Parasitological indices of Neopolystoma sp. and T. achavali suggest to be occasional infections; whereas infection by Eustrongylides sp. could be considered accidental. About Telorchiidae, there was no co-occurrence of the species of this group for the examined hosts. In relation to host’s gender, it was observed that infections by S. contortus, F. affinis, C. emydidius and T. corti had higher rates in females, showing a more intimate association with the females of T. dorbigni. The results suggest that human impact on the environment could affect the infrapopulacional dynamics of parasite species influencing the presence and rates of infection of helminths or exacerbating heterogeneities related to host’s gender.