New observations from the intestinal fauna of Kerodon rupestris (Wied, 1820) (Rodentia, Cavidae), Brazil: a checklist spanning 30,000 years of parasitism

Back to basics: Could simple experiments resolve important parasitology enigmas? The rarity of Ascaris eggs compared with Trichuris eggs in archeology and other contexts

Most parasitologists face a conundrum throughout their careers: 'which parasite eggs are more resistant to environmental stress, Ascaris spp. or Trichuris spp.?' In this analysis, our experimental and statistical analyses demonstrated that Trichuris sp. is more resistant than Ascaris sp. We highlight that desiccation exerts a major effect on the conservation of Ascaris eggs, and this may result in an underestimation of Ascaris eggs in paleoparasitological records. This observation can be extrapolated to more modern scenarios, for example, parasitological research in animal feces from semiarid environments, where whipworms are more common than roundworms. Similarly, this could be a plausible explanation for the higher frequency and abundance of whipworms than roundworms, when other hypotheses are unsupported.

Description of Pudica wandiquei n. sp. (Heligmonellidae: Pudicinae), a nematode found infecting Proechimys simonsi (Rodentia: Echimyidae) in the Brazilian Amazon

A new species of nematode parasite of the subfamily Pudicinae (Heligmosomoidea: Heligmonellidae) is described from the small intestine of Proechimys simonsi (Rodentia: Echimyidae) from the locality of Nova Cintra in the municpality of Rodrigues Alves, Acre state, Brazil. The genus Pudica includes 15 species parasites of Neotropical rodents of the families Caviidae, Ctenomyidae, Dasyproctidae, Echimyidae, Erethizontidae, and Myocastoridae. Four species of this nematode were found parasitizing three different species rodents of the genus Proechimys in the Amazon biome. Pudica wandiquei n. sp. can be differentiated from all other Pudica species by the distance between the ends of rays 6 and 8 and the 1-3-1 pattern of the caudal bursa in both lobes.