Oswaldocruzia franciscoensis n. sp. (Nematoda: Molineidae) in Leptodactylus macrosternum Miranda-Ribeiro, 1926 (Anura: Leptodactylidae) from Caatinga morphoclimatic domain, Brazil: morphological and molecular characterisation.

A new species of Oswaldocruzia Travassos, 1917 (Nematoda, Molineidae), parasite of Leptodactylus macrosternum Miranda-Ribeiro, 1926 (Anura: Leptodactylidae), from Caatinga morphoclimatic domain, Brazil, is described based on morphological and molecular data. Oswaldocruzia franciscoensis n. sp. is characterised by an anterior extremity with a cephalic vesicle divided into two portions, a body covered by cuticular longitudinal ridges, and cervical alae. Males of the new species have caudal bursa of type I with a 2-1-2 pattern, spicules divided into a shoe, bifurcated fork, and blade with two unequal branches, in which the longer branch bifurcates at its distal portion end and the smaller branch with three distal processes, each with distal bifurcations. Females have didelphic and amphidelphic uteri, an ovijector divided into vestibule, anterior and posterior sphincters, and anterior and posterior infundibula. The new species differs from its Neotropical congeners that have caudal bursa of type I, based on the presence of cervical alae and by having a spicular blade distally divided into two unequal branches, with the longer branch bifurcating at its distal portion and smaller branch with three distal processes, each distally bifurcated. The partial 18S rDNA sequence generated for Oswaldocruzia franciscoensis n. sp. is the first of a representative belonging to this genus in the Neotropical region.

Do host habitat use and cospeciation matter in the evolution of Oswaldocruzia (Nematoda, Molineidae) from neotropical amphibians?

The genus Oswaldocruzia Travassos, 1917 includes approximately 90 species that are parasitic on amphibians and reptiles around the world, of which 43 occur in the neotropical region. However, molecular data supporting the taxonomic status of most species of the genus are scarce, and their phylogenetic relationships remain unknown. Using specimens of four molineid taxa (Oswaldocruzia belenensis Santos, Giese, Maldonado Jr. and Lanfredi, 2008; Oswaldocruzia chabaudi Ben Slimane & Durette-Desset, 1996, Oswaldocruzia chambrieri Ben Slimane & Durette-Desset, 1996 and Kentropyxia hylae Feitosa, Furtado, Santos and Melo, 2015) from amphibian hosts collected in different regions of Pará, Brazil, we conducted morphological studies, molecular analyses and phylogenies (maximum likelihood and Bayesian inference) using the cytochrome c oxidase subunity I (Cox1) gene. The newly generated sequences were compared with those of ten publicly available Cox1 sequences of Oswaldocruzia from Mexico. Our findings demonstrated significant differences between the sequences of amazonian specimens and sequences from specimens collected in Mexico, and we suggest that host-parasite cospeciation or habitat use might be related to molineid evolution in amphibian hosts. Additionally, this work presents new hosts and new geographical records for species of Oswaldocruzia from the neotropics.

Morphological and Molecular Identification of Nematodes in The Tayra Eira Barbara from Campeche, Mexico.

The tayra Eira barbara is a Neotropical mustelid considered as an endangered species by Mexican environmental authorities. Despite the considerable information available on the biology and ecology of E. barbara, little is known about its helminth fauna. Here, we provided new records of nematodes from a road-killed tayra in Calakmul, Campeche, Mexico. The species identification of nematodes was based on morphological studies and molecular analysis of fragments of the 28S gene. The tayra specimen was infected by three nematodes: Molineus sp., Physalopterinae gen. sp. and Angiostrongylus vasosum. To our knowledge, this study is the first to report the natural infection of E. barbara with Molineus sp. and Physalopterinae gen. sp. Our study provides the first nucleotide sequences of nematodes parasitizing E. barbara providing a starting point against which future studies may be compared.

Gastrointestinal nematodes of Paramelomys platyops (Rodentia: Muridae) from Papua Indonesia and Papua New Guinea with the descriptions of a new genus and five new species of Heligmonellidae (Nematoda: Trichostrongylina) and a key to the species of Hughjonestrongylus.

Nematodes from six families, comprising 20 species identified to genus level and three to subfamily level as well as juveniles and a heligmonellid that could not be identified further, were recovered from 34 individuals of Paramelomys platyops, one P. cf playops and one Melomys sp. (Muridae: Murinae: Uromys Division) from Papua Indonesia and Papua New Guinea. Ascaridid larvae, a capillariid, Capillaria s. l., two putative species of the Nippostrongylinae and a small number of heligmonellid males and females, could not be identified further. The rictulariid Pterygodermatites sp. (females only) had not been reported previously from Sahulan Old Endemic fauna while three species, the oxyurid Syphacia longecauda , the molineid Hepatojarakus pyknofasciatus, and the spirurid Protospirura kaindiensis, had. The remaining species, all heligmonellids, included the brevistriatine Macrostrongylus ingens and 14 nippostrongyline species. Of these, Hughjonestrongylus amplicauda, H. singauwaensis, Melomystrongylus sepikensis, Mawsonema mokwanense, Odilia mackerrasae and Parasabanema szalayi had been reported previously. Species of Hasanuddina, Montistrongylus and Sanduanensis possibly as yet undescribed, could not be identified further. Flannerystrongylus abulus n. gen., n. sp. differed from all 41 genera described to date in having a synlophe of 14-16 evenly sized ridges with a sub frontal orientation. Hasegawanema yuroense n. sp. with 21-23 synlophe ridges was distinguished from its congeners by a combination of characters including length of spicule, cuticularisation of the genital cone, the proportions of the ovejector and the size of the eggs. Hughjonestrongylus pervulgatus n. sp., H. vanimoensis n. sp. and H. wanumaensis n. sp. were distinguished from all other species of Hughjonestrongylus and each other by a combination of characters including the number of synlophe ridges 25-30, 18, 22-23 in the mid body respectively, and spicule length, proportions of the ovejector and shape of the female tail. A key to the species of Hughjonestrongylus is provided. Species richness was greater than that recorded for P. lorentzii and P. rubex with about 86% of possible species found, as indicated by bootstrap analysis. The helminth assemblage was dominated by heligmonellids with eight species being unique to P. platyops. Paramelomys lorentzii is found at altitudes up to 1500 m and may provide a link between the lowland P. platyops and the highland P. rubex, thus facilitating the distribution of helminth species held in common.