An integrative taxonomy study reveals a rare new species of the genus Creptotrema (Trematoda: Allocreadiidae) in an endangered frog in South America.

During an ecological study with a near-endangered anuran in Brazil, the Schmidt's Spinythumb frog, Crossodactylus schmidti Gallardo, 1961, we were given a chance to analyze the gastrointestinal tract of a few individuals for parasites. In this paper, we describe a new species of an allocreadiid trematode of the genus Creptotrema Travassos, Artigas & Pereira, 1928, which possesses a unique trait among allocreadiids (i.e., a bivalve shell-like muscular structure at the opening of the ventral sucker); the new species represents the fourth species of allocreadiid trematode parasitizing amphibians. Besides, the new species is distinguished from other congeners by the combination of characters such as the body size, ventral sucker size, cirrus-sac size, and by having small eggs. DNA sequences through the 28S rDNA and COI mtDNA further corroborated the distinction of the new species. Phylogenetic analyses placed the newly generated sequences in a monophyletic clade together with all other sequenced species of Creptotrema. Genetic divergences between the new species and other Creptotrema spp. varied from 2.0 to 4.2% for 28S rDNA, and 15.1 to 16.8% for COI mtDNA, providing robust validation for the recognition of the new species. Even though allocreadiids are mainly parasites of freshwater fishes, our results confirm anurans as hosts of trematodes of this family. Additionally, we propose the reallocation of Auriculostoma ocloya Liquin, Gilardoni, Cremonte, Saravia, Cristóbal & Davies, 2022 to the genus Creptotrema. This study increases the known diversity of allocreadiids and contributes to our understanding of their evolutionary relationships, host-parasite relationships, and biogeographic history.

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.

Can differences between continental and insular habitats influence the parasites communities associated with the endemic frog Haddadus binotatus?

Habitats characterized by geographic isolation such as islands have been studied using different organisms as models for understanding the dynamic and insular patterns of biodiversity. Determinants of parasite richness in insular host populations have been conducted mainly with mammals and birds, showing that parasite richness decreases in insular areas. In the present study, we predicted that the type of environment (insular or continental) can influence the richness, diversity and abundance of parasites associated with the endemic frog Haddadus binotatus (Spix, 1824). We sampled frogs in two insular and two mainland fragments to survey their helminth parasites. The total richness was composed of 15 taxa of Nematoda and two of Acanthocephala, and the community composition of the two islands had more similarities between them than the two mainland localities. The insular effect was positive for richness and abundance of helminths, and no significant effect was observed on helminth diversity - even the mean diversity presented high numbers for the islands. We presumed that insular hosts could have lost some parasites in the colonization process when these continental islands were separated from the mainland, approximately 11,000 years ago. However, the high richness and abundance on islands can be explained by an epidemiological argument, which considers high population density due to insularity and other features of the host as factors that increase parasite transmission success among individuals.

New records of Helminths in Reptiles from five states of Brazil / Novos registros de helmintos em répteis de cinco estados do Brasil

Abstract Forty five specimens representing nine species of reptile (Salvator merianae, Enyalius bilineatus, Amphisbaena alba, Xenopholis undulatus, Chironius fuscus, Helicops angulatus, Chironius flavolineatus, Erythrolamprus viridis and Crotalus durissus) collected in five Brazilian states were examined for helminths. Twelve helminth species were found as follow: nine Nematoda (Physaloptera tupinambae, Strongyluris oscari, Paracapillaria sp., Dracunculus brasiliensis, Physaloptera liophis, Serpentirhabias sp. 1, Serpentirhabias sp. 2, Serpentirhabias sp. 3 and Aplectana sp.), one Cestoda (Semenoviella amphisbaenia), one Trematoda (Paracotyletrema sp.), and one Acantocephala (Centrorhynchus sp.). Ten new host records and seven new locality records were reported.

Resumo Quarenta e cinco espécimes que representa nove espécies de répteis (Salvator merianae, Enyalius bilineatus, Amphisbaena alba, Xenopholis undulatus, Chironius fuscus, Helicops angulatus, Chironius flavolineatus, Erythrolamprus viridis e Crotalus durissus) coletados em cinco estados brasileiros foram examinados para helmintos. Foram encontrados doze espécies de helmintos sendo: nove Nematoda (Physaloptera tupinambae, Strongyluris oscari, Paracapillaria sp., Dracunculus brasiliensis, Physaloptera liophis, Serpentirhabias sp. 1, Serpentirhabias sp. 2, Serpentirhabias sp. 3 e Aplectana sp.), um Cestoda (Semenoviella amphisbaenia), um Trematoda (Paracotyletrema sp.) e um Acantocephala (Centrorhynchus sp.). Dez novos registros de hospedeiros e sete novos registros de localidade foram relatados.

Helminths of Dermatonotus muelleri (Anura: Microhylidae) from Northeastern Brazil.

The helminth fauna associated with Muller's termite frog, Dermatonotus muelleri, from the southern region of Ceará State, Brazil, was studied. The species richness was 6 helminth taxa, including cystacanths of Acanthocephala and 5 nematode species: Aplectana membranosa, Parapharyngodon silvoi, Raillietnema spectans, larvae of Physaloptera sp., and an unidentified nematode. The overall prevalence was 88.6%, with an average intensity of infection of 123.7 ± 26.3. The nematode Raillietnema spectans presented the highest prevalence and was the most abundant ( d = 0.670). Host body size did not influence the intensity of infection nor the richness of helminth species. This study increases the body of knowledge about the diversity of helminth fauna associated with Dermatonotus muelleri from northeastern Brazil, extending the record of hosts and the geographic distribution of these helminth species.

New records of Helminths in Reptiles from five states of Brazil.

Forty five specimens representing nine species of reptile (Salvator merianae, Enyalius bilineatus, Amphisbaena alba, Xenopholis undulatus, Chironius fuscus, Helicops angulatus, Chironius flavolineatus, Erythrolamprus viridis and Crotalus durissus) collected in five Brazilian states were examined for helminths. Twelve helminth species were found as follow: nine Nematoda (Physaloptera tupinambae, Strongyluris oscari, Paracapillaria sp., Dracunculus brasiliensis, Physaloptera liophis, Serpentirhabias sp. 1, Serpentirhabias sp. 2, Serpentirhabias sp. 3 and Aplectana sp.), one Cestoda (Semenoviella amphisbaenia), one Trematoda (Paracotyletrema sp.), and one Acantocephala (Centrorhynchus sp.). Ten new host records and seven new locality records were reported.

Helminth Community Dynamics in a Population of Pseudopaludicola Pocoto (Leptodactylidae: Leiuperinae) from Northeast-Brazilian.

Climatic variation in low latitudes influences the dynamics and structure of parasite communities. Environmental changes caused by dry and rainy seasons alter prevalence and abundance of endoparasite communities. In addition to providing a list of the helminth species associated with the swamp frog Pseudopaludicola pocoto, this study aimed to investigate the effects of rainfall and temperature on parasitological descriptors of helminths associated with P. pocoto in an area of the semiarid zone. A total of 817 swamp frog specimens were collected between 2013 and 2017, with four sampling expeditions during the dry season and four during the rainy season. Environmental parameters of temperature and rainfall were compared to the parasitological descriptors of prevalence, abundance and mean infection intensity of the parasite community using a multivariate linear regression. A richness of eight parasite species was identified, including Nematoda (Rhabdias sp., Cosmocerca parva, Oxyascaris oxyascaris, Physaloptera sp., Brevimulticaecum sp., Spiroxys sp. and unidentified nematode) and Acanthocephala (cystacanths). Rainfall levels had a significant effect on the infection intensity of Rhabdias sp. being the presence of this species higher during the rainy season, whereas no influence of temperature was observed on the helminth community.

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.

Helminth communities of Leptodactylus latrans (Anura: Leptodactylidae) from the Atlantic rainforest, south-eastern Brazil.

The helminth fauna associated with Leptodactylus latrans, a large frog living in a disturbed environment of Atlantic rainforest in south-eastern Brazil, was evaluated. We found eight helminth taxa, including five nematode species, Falcaustra mascula, Oswaldocruzia subauricularis, Physaloptera sp., Rhabdias sp. and an unidentified cosmocercid, two trematodes, Gorgoderina parvicava and Haematoloechus fuelleborni, and one larval cestode. The overall prevalence of infection was 63.2% with a mean intensity of 11.3 ± 3.8. The cosmocercid nematode and O. subauricularis showed the highest prevalences, although the trematode G. parvicava was the most abundant and dominant parasite species. Host size positively influenced both the intensity of infection and parasite species richness. Our data suggest that the juvenile individuals of L. latrans are more susceptible to parasitic infection than the adults. The comparison of the similarity of this community component with that found in other studies in South America shows that, as well as the characteristics of the host, the sampling area also influences the parasitic fauna. Therefore, the results of this study agree that the helminth communities of frogs have relatively low species richness and dominance of generalist species.

Endoparasites infecting the semiaquatic coral snake Micrurus surinamensis (Squamata: Elapidae) in the southern Amazonian region, Mato Grosso state, Brazil.

A parasitological survey was conducted in specimens of the semiaquatic coral snake Micrurus surinamensis, a poorly known South American elapid. Four specimens collected at the southern Amazon region in the Brazilian state of Mato Grosso were analyzed for endoparasites. Three parasite species were recovered from the snake hosts: the pentastomid Sebekia oxycephala, the nematode Physaloptera sp. and the trematode Opisthogonimus lecithonotus. This represents new locality and host record for S. oxycephala and O. lecithonotus.

Synanthropy of mosquitoes and sand flies near the Aimorés hydroelectric power plant, Brazil.

The environmental changes resulting from the construction of hydroelectric dams may affect the fauna of insect vectors and consequently the epidemiology of the diseases they transmit. This work examined the mosquito and sand fly fauna in the area of the Aimorés hydroelectric power plant, analyzing the seasonal distribution and the degree of species synanthropy in different ecotopes. Between November, 2008 and September, 2009, entomological captures were performed with the help of HP light traps in the rural, urban, and forest areas of Aimorés, Ituêta, Resplendor, and Baixo Guandu counties. The fauna proved to be quite diversified. Twenty-two species of mosquitoes and 11 species of sand flies were found. Culex quinquefasciatus was predominant among mosquitoes (76.7%), while Lutzomyia intermedia prevailed among sand flies (34.5%). Some of the captured species have medical interest. Supported by the high degree of synanthropy, those species reinforce the need for epidemiological surveillance.

First record of Trypanosoma chattoni in Brazil and occurrence of other Trypanosoma species in Brazilian frogs (Anura, Leptodactylidae).

The present study provides the first record of Trypanosoma chattoni Mathis and Leger, 1911, in a new host, Leptodactylus fuscus Schneider, 1799 (Anura, Leptodactylidae), and the occurrence of Trypanosoma rotatorium-like species in Leptodactylus chaquensis Cei, 1950. The anurans were captured in the State of Mato Grosso, Brazil. Blood samples were obtained by cardiac puncture, and blood smears were examined for the presence of hemoparasites. The Trypanosoma rotatorium-like species in this study refers to a short-bodied trypomastigote that has a conspicuous undulating membrane but lacks a free flagellum; T. chattoni refers to a monomorphic parasite that has a rounded body, a kinetoplast adjacent to the nucleus, and a short flagellum.