Phylogenetic position of Gorgoderina parvicava Travassos, 1922 (Digenea: Gorgoderidae), a parasite of Leptodactylus labyrinthicus (Spix, 1824) (Anura: Leptodactylidae) in Brazil.

During a parasite survey in Brazilian amphibians from São Paulo state, Brazil, Gorgoderina parvicava Travassos, 1922 was found in the urinary bladder (11 adult worms) and (five juvenile worms) in the kidneys of the pepper-frog Leptodactylus labyrinthicus (Spix, 1824). Parasites were examined by microscopy and 28S rDNA and COI gene were sequenced and analyzed for the molecular study. The phylogenetic reconstructions resulted in identical topologies with highly supported values in the nodes in most clades using Maximum likelihood and Bayesian inference methods and positioned G. parvicava in the subclade formed by species of subfamily Gorgoderinae parasitizing the urinary bladder of amphibians. Molecular phylogenetic data showed that this species is related to other species of Gorgoderina. In addition, new molecular data and the analyses of genetic distances provide extra comparative data, which can be applied in further investigations on the taxonomic status and the diversity among Gorgoderina spp. and host-parasite relationships.

First molecular assessment on Cosmocerca spp. from Brazilian anurans and description of a new species of Cosmocerca (Ascaridomorpha: Cosmocercoidea) from the white-spotted humming frog Chiasmocleis albopunctata (Boettger, 1885) (Anura: Microhylidae).

Cosmocerca spp. are common nematode parasites of amphibians. We provide herein molecular data for two species of Cosmocerca and describe a new species, Cosmocerca albopunctata n. sp., using light microscopy and molecular data (cytochrome c oxidase subunit 1 - COI mtDNA). Cosmocerca albopunctata n. sp. can be easily distinguished from other congeneric species by the combination of characteristics such as body size, length of spicules and gubernaculum, and the arrangements and number of caudal papillae (7 + 1:1 + 1:6). The phylogenetic results based on the partial COI mtDNA sequences clustered the new species in a monophyletic clade along with the other sequences of Cosmocerca spp. Therefore, our results contribute to the knowledge about the species diversity and genetic data for Cosmocerca spp. in the Neotropical region.

A new species of Rhabdias (Nematoda: Rhabdiasidae), a lung parasite of Pseudopaludicola pocoto (Anura: Leptodactylidae) from north-eastern Brazil: description and phylogenetic analyses.

Rhabdias pocoto n. sp. is herein described from the lungs of the swamp frog Pseudopaludicola pocoto Magalhães, Loebmann, Nogueira, Kokubum, Baptista, Haddad & Garda, 2014, from the Caatinga biome in the state of Ceará, in north-eastern Brazil. The new species is characterized by a body that dilates posteriorly, six small lips (protuberances) and two rounded lateral expansions of cuticular inflation on the anterior end, each containing an amorphous gland-like structure inside and a short and conical tail. Additionally, molecular analysis and comparison of the partial mitochondrial cytochrome c oxidase I sequence of R. pocoto n. sp. revealed genetic divergence between the new species and the sequences of Rhabdias spp. previously deposited in GenBank. Phylogenetic analysis grouped the new taxon into the R. pseudosphaerocephala species complex + R. glaurungi clade. The new discovery represents the 19th species of Rhabdias spp. described in the Neotropical region, the ninth in Brazil and the first species of Rhabdias found parasitizing South American frogs of the genus Pseudopaludicola, as well as the first Caatinga biome species of Rhabdias.

A new species of Creptotrematina (Trematoda: Allocreadiidae) from characid fishes of Brazil: morphological and molecular data.

A new species of Creptotrematina Yamaguti, 1954 was collected from characid fishes, Astyanax fasciatus (Cuvier, 1819) and Astyanax lacustris Lucerna & Soares, 2016 from the Batalha River in the State of Sao Paulo, Brazil. The new species most closely resembles Creptotrematina aguirrepequenoi, but differs by the elongated shape of vitelline follicles, the extension of these follicles in the posterior end of body and the fact that they are not confluent. The morphological differences were confirmed through molecular data. Three specimens were sequenced, and molecular analyses were based on the internal transcribed spacers 2 and D1-D3 domains of the 28S ribosomal RNA gene. The obtained topologies showed the new species as a sister taxon of C. aguirrepequenoi, a species originally described from Astyanax mexicanus in Mexico, and later found in Astyanax aeneus in Costa Rica. Isolates of the new species are reciprocally monophyletic, and genetic distance values are similar to those observed in other species pairs within Allocreadiidae. These findings corroborate that the genus Creptotrematina is mostly a parasite of characids, and widely extended across the Americas, with representative species occurring between Argentina and northern Mexico.

Trinigyrus spp. (Monogenea: Dactylogyridae) from Brazilian catfishes: new species, molecular data and new morphological contributions to the genus.

This study describes two new species, Trinigyrus anthus n. sp. and Trinigyrus carvalhoi n. sp., from gills of Hypostomus spp. from the Upper Paraná River basin, Brazil. Trinigyrus peregrinus is redescribed based on examination of its holotype, paratypes and new material of specimens parasitizing Pterygoplichthys ambrosettii, also from the Upper Paraná River basin, Brazil. New morphological features were included in the diagnosis of the genus, such as the presence of a sclerotized border on the anchor base, and a weakly sclerotized fringe on the base of the male copulatory organ (MCO). Trinigyrus anthus n. sp. differs from other congeners by the shape of the MCO, presenting an enlarged base with sclerotized fringes resembling flower petals. Trinigyrus carvalhoi n. sp. and T. peregrinus are similar but can be differentiated from each other mainly by the sclerotization of the vagina (absent in the new species), and the morphology of the MCO (C-shaped versus one counterclockwise circle, respectively). For the first time, gene sequences of Trinigyrus spp. from Brazil were obtained (partial ribosomal 28S and mitochondrial cytochrome c oxidase I (mtCOI)). The genetic divergences among the new species and T. peregrinus varied from 2 to 3% (6‒18 pb) based on sequences of 28S ribosomal DNA (rDNA), and 6-7% (83‒92 pb) using mtCOI. Phylogenetic analyses based on partial 28S rDNA revealed that Trinigyrus, Heteropriapulus and Unilatus formed a monophyletic and well-supported clade of monogeneans from Neotropical freshwater loricariids, suggesting a closer relationship among these dactylogyrids and their hosts.

Morphology and molecular characterization of Demidospermus spirophallus n. sp., D. prolixus n. sp. (Monogenea: Dactylogyridae) and a redescription of D. anus in siluriform catfish from Brazil.

The present study describes Demidospermus spirophallus n. sp. and Demidospermus prolixus n. sp. (Monogenea, Dactylogyridae) from the siluriform catfish Loricaria prolixa Isbrücker & Nijssen, 1978 (Siluriformes, Loricariidae) from the state of São Paulo, Brazil, supported by morphological and molecular data. In addition, notes on the circumscription of the genus with a redescription of Demisdospermus anus are presented. Demidospermus spirophallus n. sp. differed from other congeners mainly because of the morphology of the male copulatory organ (MCO), which exhibited 2½ counterclockwise rings, a tubular accessory piece with one bifurcated end and a weakly sclerotized vagina with sinistral opening. Demidospermus prolixus n. sp. presents a counterclockwise-coiled MCO with 1½ rings, an ovate base, a non-articulated groove-like accessory piece serving as an MCO guide, two different hook shapes, inconspicuous tegumental annulations, a non-sclerotized vagina with sinistral opening and the absence of eyes or accessory eyespots. The present study provides, for the first time, molecular characterization data using the partial ribosomal gene (28S) of two new species of Demidospermus from Brazil (D. spirophallus n. sp. and D. prolixus n. sp.), and Demidospermus anus from Loricariichthys platymetopon Isbrücker & Nijssen, 1979 collected in the Upper Paraná River floodplain, Brazil. Additionally, a revision of the species composition of this genus and others that occur in catfish is proposed to elucidate problems with their circumscription. The Brazilian species of Demidospermus clustered together as sister taxa among Neotropical dactylogyrids from siluriforms. The morphological characterization of D. spirophallus n. sp. and D. prolixus n. sp., and the molecular data of the three species in the present study will extend knowledge about this monogenean genus from the Neotropical region, and provide new information for future phylogeny studies.

Morphometric and phylogenetic analyses of Serpentirhabdias viperidicus n. sp. (Nematoda: Rhabdiasidae) from the lancehead snake Bothrops moojeni Hoge, 1966 (Reptilia: Serpentes: Viperidae) in Brazil.

Serpentirhabdias viperidicus n. sp. (Nematoda: Rhabdiasidae) is described from the lungs of the 'Brazilian lancehead' Bothrops moojeni (Hoge, 1966) from the savannah in São Paulo State, Brazil. The new species is the eighth species of Serpentirhabdias described in the Neotropical region, and differs from other species mainly by a combination of characters: lips slightly notable, presence of fine striations at posterior ends, presence of two parallel lines with intercalated pores, a pore-shaped phasmid situated at the level of the anal aperture and another two in the posterior half of the tail. It is the first species of Serpentirhabdias reported in this snake host and the second species of this genus found parasitizing South American viperidian snakes. Molecular phylogenetic analysis using ribosomal (ITS and 28S partial) genes confirms Serpentirhabdias viperidicus n. sp. as a new species that clustered in the Serpentirhabdias clade, sister taxon to Serpentirhabdias fuscovenosa and Serpentirhabdias elaphe. This is the first description of Serpentirhabdias species from Brazil using molecular approaches and morphological characters to confirm the monophyly of this recent genus.