Helminth community structure of the white-bellied woolly mouse opossum Marmosa constantiae Thomas, 1904 in Central-West Brazil.

Marmosa constantiae is a species of marsupial restricted to the central portion of South America. In Brazil, it occurs in the northwestern region including five states of the Amazon, Cerrado, and Pantanal biomes. However, there is no study of the helminth fauna or helminth community structure for this marsupial. The aims of this study were to describe the species composition and to analyse the structure of the helminthic community of M. constantiae in an area of the Amazon Arc in Sinop, north of the state of Mato Grosso, Brazil. Parasites were searched in 53 specimens of this marsupial, among which 44 were infected with at least one helminth species. Parasitic helminths were counted and identified. Nine species were collected: seven nematodes, one cestode, and one acanthocephalan. The most abundant species were Gracilioxyuris agilisis, Travassostrongylus scheibelorum, Pterygodermatites sinopiensis, and Subulura eliseae. These species were the only dominant ones in the component community. No significant differences were observed in the abundance and prevalence of helminths between male and female hosts. Host body size significantly influenced helminth abundance in males. The pattern of community structure considering the infracommunities in this locality indicated more species replacement than species loss along the environmental gradient. This is the first study to report the helminth fauna and the helminth community structure of M. constantiae.

Subulura eliseae sp. n. (Ascaridida: Subuluroidea), a parasite of Marmosa spp. from Amazon rainforest, Brazil.

The parasite biodiversity of mouse opossums in Brazil remains incompletely explored. We describe a new species of Subulura (Ascaridida: Subuluroidea) from the large intestine of the white-bellied woolly mouse opossum, Marmosa constantiae, based on the results of light and scanning electron microscopy (SEM). We also partially sequenced the mitochondrial cytochrome c oxidase I (MT-CO1) gene of the new species, using molecular phylogenetic analyses to determine its relationships within the Subuluroidea superfamily. As molecular data on subuluroid species are extremely limited, few inferences could be drawn from our phylogenies. Our SEM observations showed the detailed morphology of the cephalic extremity, precloacal pseudo-sucker, caudal papillae, phasmids and vulva. Subulura eliseae sp. n. differs from the other four Subulura parasites species of marsupials by the number of caudal papillae and the structure dimensions, and size of the spicule. Moreover, S. eliseae sp. n. has ten pairs of caudal papillae, which is unique compared to other species. We present morphometric and molecular data on this new species, contributing to future studies on subuluroids.

First record of Pseudoryzomys simplex (Cricetidae, Sigmodontinae) in a flooded area of the Pantanal, Brazil / Primeiro registro de Pseudoryzomys simplex (Cricetidae, Sigmodontinae) em área alagada do Pantanal, Brasil

Abstract Pseudoryzomys simplex is a small to medium sized terrestrial rodent confined to lowland open areas with strong seasonal rainfall throughout the Chaco, Cerrado and Caatinga. Despite its extensive range, the species is difficult to trap. In this report we provide the first record of P. simplex in the Pantanal, where three specimens were collected in a pasture of exotic grass. The specimens are morpometrically similar to the population from Paraguay (Chaco). In this sense, our report shows how interesting a taxonomic review of the species would be to better understand the real significance of the geographic variation herein observed.

Resumo Pseudoryzomys simplex é um roedor terrestre de pequeno a médio porte que ocorre em áreas abertas de planícies com fortes precipitações sazonais ao longo dos Chaco, Cerrado e Caatinga. Apesar de sua extensa distribuição, a espécie é difícil de ser capturada. No presente estudo, fornecemos o primeiro registro de P. simplex no Pantanal, onde três espécimes foram coletados em uma pastagem de capim exótico. Os espécimes são morfometricamente semelhantes à da população do Paraguai (Chaco). Neste sentido, o nosso relatório mostra quão interessante seria uma revisão taxonômica das espécies para melhor compreender o significado real da variação geográfica aqui observada.

Endoparasites of wild animals from three biomes in the State of Mato Grosso, Brazil / Endoparasitas de animais silvestres de três biomas do Mato Grosso, Brasil

The population of wild animals is regulated by many biotic and abiotic factors, and parasites are a biotic factor that affects the dynamic and density of host populations. From 2002 to 2014, 62 wild animals from the biomes Pantanal, Amazon, and "Cerrado" (or Savanna), which died in attendance in the veterinary hospital or have been road-killed, underwent necropsy for parasitological examination. Overall, 36 species of parasites were identified from 24 host species. Among the parasites, the most prevalent order was Oxyurida (29.1%), followed by Strongylida (20.9%), Spirurida (19.4%), Ascaridida (16.2%), Pentastomida (3.2%), Echinostomida (3.2%), Gygantorhynchia (3.2%), Rhabditida (1.6%), Plagiorchiida (1.6%), and Monilimorfida (1.6%), especially nematodes, which have more biotic potential and is more easily adapted to the environment than other classes. The occurrence of endoparasites was observed more frequently in endothermic than ectothermic animals, and herein is reported eleven new host occurrences for endoparasites in wild animals. The study has contributed to the knowledge on the biodiversity of parasites in wild animals from three biomes in central-western Brazil.(AU)

Populações de animais selvagens são reguladas por diversos fatores bióticos e abióticos, e parasitas são um fator biótico que afetam a dinâmica e a densidade de populações. De 2002 até 2014, 62 animais silvestres provenientes dos biomas Pantanal, Amazônia e Cerrado, que vieram a óbito no atendimento do hospital veterinário ou foram encontrados atropelados em rodovias, foram submetidos à necropsia parasitológica. Ao todo 36 espécies de parasitas foram identificadas em 24 espécies de hospedeiros. Entre os parasitas, a ordem mais prevalente foi Oxyurida (29,1%), seguida por Strongylida (20,9%), Spirurida (19,4%), Ascaridida (16,2%), Pentastomida (3,2%), Echinostomida (3,2%), Gygantorhynchia (3,2%), Rhabditida (1,6%), Plagiorchiida (1,6%) e Monilimorfida (1,6%), destacando-se os nematódeos, por seu maior potencial biótico e facilidade de adaptação ao meio do que as demais classes. A maior ocorrência de endoparasitas foi observada em animais endotérmicos que ectotérmicos, e este estudo registra onze novas ocorrências de hospedeiros para endoparasitas de animais selvagens. O estudo contribui para o conhecimento da biodiversidade de parasitas em animais silvestres dos três biomas do Centro-Oeste do Brasil.(AU)

First record of Pseudoryzomys simplex (Cricetidae, Sigmodontinae) in a flooded area of the Pantanal, Brazil.

Pseudoryzomys simplex is a small to medium sized terrestrial rodent confined to lowland open areas with strong seasonal rainfall throughout the Chaco, Cerrado and Caatinga. Despite its extensive range, the species is difficult to trap. In this report we provide the first record of P. simplex in the Pantanal, where three specimens were collected in a pasture of exotic grass. The specimens are morpometrically similar to the population from Paraguay (Chaco). In this sense, our report shows how interesting a taxonomic review of the species would be to better understand the real significance of the geographic variation herein observed.

Genetic and morphological variability in South American rodent Oecomys (Sigmodontinae, Rodentia): evidence for a complex of species.

The rodent genus Oecomys (Sigmodontinae) comprises ~16 species that inhabit tropical and subtropical forests in Central America and South America. In this study specimens of Oecomys paricola Thomas, 1904 from Belém and Marajó island, northern Brazil, were investigated using cytogenetic, molecular and morphological analyses. Three karyotypes were found, two from Belém (2n = 68, fundamental number (FN) = 72 and 2n = 70, FN = 76) and a third from Marajó island (2n = 70, FN = 72). No molecular or morphological differences were found between the individuals with differing cytotypes from Belém, but differences were evident between the individuals from Belém and Marajó island. Specimens from Belém city region may represent two cryptic species because two different karyotypes are present in the absence of significant differences in morphology and molecular characteristics. The Marajó island and Belém populations may represent distinct species that have been separated for some time, and are in the process of morphological and molecular differentiation as a consequence of reproductive isolation at the geographic and chromosomal levels. Thus, the results suggest that O. paricola may be a complex of species.