Morphological and genetic characterization of Pterygodermatites (Paucipectines) zygodontomis (Nematoda: Rictulariidae) from Necromys lasiurus (Rodentia: Sigmodontinae) from Uberlândia, Brazil

Dentition patterns and molecular diversity of Mastophorus muris (Gmelin, 1790) (Nematoda: Spiruroidea) support a host-associated subdivision

Mastophorus muris (Gmelin, 1790) is a globally distributed parasitic nematode of broad range mammals. The taxonomy within the genus Mastophorus and the cryptic diversity among the genus are controversial among taxonomists. This study provides a detailed morphological description of M. muris from Mus musculus combined with a molecular phylogenetic approach. Moreover, descriptions and molecular data of M. muris from non-Mus rodents and wildcats complement our findings and together provide new insights into their taxonomy. The analysis of M. muris was based on light microscopy and scanning electron microscopy. The morphological description focused on the dentition pattern of the two trilobed pseudolabia. Additionally, we described the position of the vulva, arrangement of caudal pairs of papillae, spicules and measured specimens from both sexes and the eggs. For the molecular phylogenetic approach, we amplified the small subunit ribosomal RNA gene and the internal transcribed spacer, and the cytochrome c oxidase subunit 1. Mastophorus morphotypes based on dentition patterns and phylogenetic clustering indicate a subdivision of the genus in agreement with their host. We recognize two groups without a change to formal taxonomy: One group including those specimens infecting Mus musculus, and the second group including organisms infecting non-Mus rodents. Our genetic and morphological data shed light into the cryptic diversity within the genus Mastopohorus. We identified two host-associated groups of M. muris. The described morphotypes and genotypes of M. muris allow a consistent distinction between host-associated parasites.

An annotated checklist of the genus Pterygodermatites Wedl, 1861 (Nematoda: Rictulariidae), with notes on hosts and geographical distribution

Species of rictulariid nematodes belonging to the genus Pterygodermatites Wedl, 1861 are parasites of mammals with a wide geographical distribution. The taxonomy of this speciose genus is complex and based mainly on morphological traits of the cephalic structures and cuticular processes. Currently, the known species are allocated to five subgenera [P. (Paucipectines), P. (Neopaucipectines), P. (Multipectines), P. (Pterygodermatites) and P. (Mesopectines)], based on the classification proposed in 1969 by Quentin. Studies on life cycles, taxonomy, biogeography and association of these parasites with mammals peaked at the end of the 1960s. Although the momentum was lost, new species and geographic records have been added in the last 50 years. Therefore, an updated checklist of species of Pterygodermatites is presented here, based on a literature survey. Information on classification, geographical distribution and host range obtained for 68 species is presented, including a distribution map. Moreover, the main differential morphological traits related to each species are tabulated. More than 140 species from 10 different mammalian orders (Carnivora, Chiroptera, Didelphimorphia, Erinaceomorpha, Macroscelidae, Microbiotheria, Paucituberculata, Primates, Rodentia and Xenarthra) have been reported as hosts of Pterygodermatites spp. The taxonomic information here compiled can contribute to future studies on the biogeography, in addition to evolutionary and ecological aspects of this diverse but poorly known genus of parasitic nematodes of mammals.

First report of the intestinal helminth community in the broad-headed spiny-rat Clyomys laticeps (Rodentia, Echimyidae)

The broad-headed spiny rat, Clyomys laticeps, is an echimyid rodent found in open areas of Cerrado and Pantanal biomes in central Brazil and Paraguay. Little is known about the parasites associated with this semi-fossorial species, as no previous studies have been conducted on their helminth fauna. The aim of this study was to report the helminth community structure of C. laticeps inhabiting Serra de Caldas Novas State Park, a Cerrado area in central Brazil. Trappings were carried out in dry grasslands from January to October 2016, and the large and small intestines of 14 C. laticeps individuals were examined for the presence of helminths. Three nematode species were found: Fuellebornema almeidai, Pterygodermatites (Paucipectines) sp., and Subulura forcipata, and 85.7% of the studied species were infected with at least one of these helminths. F. almeidai was the most prevalent species among hosts, and S. forcipata was the most abundant. This study is the first report on helminth community structure in C. laticeps. We report a new host species and increase the known geographical range of F. almeidai, and provide the first record of Pterygodermatites (Paucipectines) sp. infecting echimyids. This is also the first report of S. forcipata in a mammal host.

Morphological and genetic description of Moniliformis necromysi sp. n. (Archiacanthocephala) from the wild rodent Necromys lasiurus (Cricetidae: Sigmondontinae) in Brazil

A new species of Moniliformis Travassos, 1915 (Acanthocephala: Moniliformidae) is described from the hairy-tailed bolo mouse, Necromys lasiurus Lund, 1840 (Cricetidae: Sigmondontinae), captured in the Brazilian Cerrado, in Uberlândia, state of Minas Gerais, Brazil. The specimens were studied by light and scanning electron microscopy. Molecular phylogenies were inferred from partial nuclear large subunit ribosomal RNA gene sequences and partial mitochondrial cytochrome c oxidase subunit I gene. The new species is distinguished from other moniliformid species by the number of rows and number of hooks per row, size of the proboscis, size of the eggs, host species and geographical distribution. Molecular phylogenies and genetic distances analyses demonstrated that Moniliformis necromysi sp. n. forms a well-supported monophyletic group with sequences of other species of Moniliformis and is distinguished from them, which agrees with the morphological characteristics, allocating the new species to this genus and to the family Moniliformidae Van Cleave, 1924. This is the first moniliformid acanthocephalan described from a wild rodent in Brazil.