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The article focuses on the first report of Aplectana hylambatis parasitizing a Brazilian anuran species Dermatonotus muelleri. It provides details about the ecological descriptors of parasitism as well as the morphological characterization of the nematode species. Other details about Aplectana hylambatis are presented.

This is the first report of Ictalurus punctatus in the middle Paranapanema river basin; the occurrence of this species may be associated with the expansion of pisciculture in cage farms in the Brazilian territory as a whole. [ABSTRACT FROM AUTHOR]

A mass of free myxozoan spores was found in the gill filaments of specimens of Cetopsorhamdia iheringi Schubart and Gomes, 1959, popularly known as "three-barbeled catfishes" (Heptapteridae, Siluriformes) collected in streams of the Middle Paranapanema River, Upper Paraná River basin, in the state of São Paulo, Brazil. Morphological and molecular analysis identified the spores as Myxobolus imparfinis Vieira, Tagliavini, Abdallah and Azevedo, 2018. The ultrastructural morphology of this parasite is described here for the first time. Differences were observed in the number of coils of the polar filament as well as some organelles not previously described for this species. Asynchronous development was also observed, with the presence of both mature and immature spores. This is the first report of a myxozoan parasitizing C. iheringi and the first geographical record of myxozoan parasites in streams of the Middle Paranapanema River. The new data improve the original description of the species and add to the knowledge of host-parasite interactions and distribution. [ABSTRACT FROM AUTHOR]

A new genus of dactylogyrid monogeneans (Ancyrocephalinae), Paracosmetocleithrum n. gen., is erected to accommodate P. trachydorasi n. sp. from Trachydoras paraguayensis (Siluriformes: Doradidae) in the Upper Paraná River basin, Brazil. The new genus differs from Neotropical dactylogyrids in the presence of a well-developed ornamentation in the middle portion of the ventral bar, and a sclerotized patch on the surface of the dorsal bar with an inconspicuous medial process that possesses two submedial projections arising from the tapered ends of this patch. In addition, Demidospermus rhinelepisi n. sp. is described from Rhinelepis aspera (Siluriformes: Loricariidae). The new species, which is the fifth species of the genus described from loricariids, can be differentiated from congeners by the possession of a sclerotized patch attached to the middle portion of the ventral bar, and by morphology of the accessory piece, which presents broad ends, tapering in the centre, rounded proximal end, distal end folding on both sides with folds extending to approximately ¾ of the accessory piece length. Molecular data on both new species are also provided and species composition of Demidospermus , recently revealed as polyphyletic by molecular studies including the present one, is discussed. [ABSTRACT FROM AUTHOR]

Rhabdias fuelleborni was described by Travassos (1926), who identified it in the lungs of Rhinella gr. marina (= Bufo marinus) from São Paulo. Later, Kloss (1971) added new information on the morphology and diagnosis of the species and new data on host and localities. However, its taxonomic status remains uncertain, due in particular to the morphological uniformity of Rhabdias spp., while the original description lacks important morphological data. In the present study, we found and reevaluated the type series of R. fuelleborni , as well as examining fresh material obtained from the type host and type locality, using light and scanning electron microscopy and molecular tools. The type series was deposited by Travassos (1926), and according to museum records the type locality is Paraty, Rio de Janeiro, Brazil. Our morphological and molecular analyses reinforce the taxonomic validity of this species, while molecular phylogeny identified a close relationship between R. fuelleborni and Rhabdias sp.4 and Rhabdias sp. from other studies, and from bufonids. Also R. fuelleborni are sister taxa with R. cf. stenocephala from Leptodactylidae from the northeast of Brazil and R. vencesi from Boophis madagascarariensis, Madagascar, according to mitochondrial COI gene. • Rhabdias fuelleborni described by Travassos (1926) was collected from the type host and type locality; • Morphological analyses were performed to reinforce the taxonomic validity of this species; • Molecular analyses using mitochondrial COI gene also using GMYC and ABGD methods, concluded that R. fuelleborni is a putative species, not a species complex. [ABSTRACT FROM AUTHOR]

Henneguya polarislonga n. sp. is described from the gills of Astyanax lacustris (Lütken, 1875) (Characiformes, Characidae) from streams of the Middle Paranapanema River, Upper Paraná River basin, in the São Paulo State, Brazil. The proposed new species is supported by a combination of morphological and molecular characterization (partial fragment of the SSU rDNA). Thirty specimens of A. lacustris were analyzed and myxospores were found in the gill lamellae of one specimen (Prevalence = 3.3%). Henneguya polarislonga n. sp. was morphometrically and genetically distinct from other Henneguya spp. previously described in Astyanax spp., mainly differing in the total length and caudal appendages length of the mature myxospores. Comparative analysis of the SSU rDNA sequences revealed that Seisactinomyxon-type actinospores previously reported parasitizing oligochaetes are developmental stages of the life cycle of Henneguya polarislonga n. sp. (similarity of 99.9%). This is the first time that an actinospore and a myxospore are correlated through molecular analysis in Brazil, contributing to the knowledge of the myxozoan ecology and biodiversity. • A new myxosporean species is described from the gill lamellae of Astyanax lacustris. • A new species was denominated Henneguya polarislonga n. sp. • An insight about the life cycle of Henneguya from Brazil is presented. • This research contributes to the knowledge of myxosporean diversity in South America. [ABSTRACT FROM AUTHOR]

In March 2010, 44 specimens of Astyanax altiparanae Garutti & Britski, 2000, commonly known as "lambari do rabo amarelo", collected from the Peixe river in the state of São Paulo, Brazil were analyzed. Out of these 44 fishes, 38 had at least one species of metazoan parasite. Fifteen metazoan parasites species were collected and identified: Urocleidoides trinidadensis, Diaphorocleidus kabatai, Diaphorocleidus orthodusus, Diaphorocleidus sp., Urocleidoides sp., Trinibaculum altiparanae, Gyrodactylus sp., Jainus hexops, Contracaecum sp., Procamallanus (Spirocamallanus) inopinatus, Vaigamus sp., Amplexibranchius bryconis, Ergasilus sp., Zonocotyloides haroltravassossi and Henneguya sp. Six species of parasites presented a prevalence of over 10%. Weight and length of fishes didn't influence the parasitism. All parasites presented an aggregated distribution. The parasite community of Astyanax altiparanae from the Peixe river was characterized as having high richness and low uniformity. [ABSTRACT FROM AUTHOR]

Although Brazil is a hotspot for snake species, there is a lack of information on the biodiversity of haemoparasites infecting these hosts. Thus, the present study aimed to bring new insights on the diversity of species of Hepatozoon (Apicomplexa: Adeleorina: Hepatozoidae) infecting Brazilian snakes from the Midwest and Southeast regions. The snakes were captured from 2018 to 2020 from the states of Mato Grosso, Mato Grosso do Sul, Goiás, and São Paulo. Three to five blood smears were made and the remaining blood sample was stored for further molecular analysis. Moreover, histopathological slides of the organs were stained with haematoxylin-eosin. Regarding molecular diagnosis, PCR was performed targeting different regions of the 18S rRNA gene of apicomplexan parasites. From the 13 free-living snakes screened, ten (76.92%) were found infected with Hepatozoon spp. Based on morphological and morphometric tools, five different morphotypes of species of Hepatozoon gamonts were detected. Molecular data and phylogenetic analysis support the morphological data, identifying five species of Hepatozoon from snakes, of which three species belong to previously described species, Hepatozoon cevapii , Hepatozoon cuestensis, and Hepatozoon quagliattus, with a genetic similarity of 100% (based on the 18S rRNA genetic marker). The present study identifies and describes two new species of Hepatozoon , Hepatozoon annulatum sp. nov. infecting the snake Leptodeira annulata and Hepatozoon trigeminum sp. nov. infecting the snake Oxyrhopus trigeminus. Thus, based on morphological and molecular data the present study provides new insights on haemogregarine diversity infecting Brazilian snakes from the Midwest and Southeast regions. [ABSTRACT FROM AUTHOR]

About forty-two species of Myxobolus have been previously described to parasitize characiform fishes in South America. Here, we described a new myxozoan species, Myxobolus parodontidis n. sp., in the gills of Apareiodon piracicabae (Characiformes, Parodontidae) from the streams of the Middle Paranapanema River basin, Brazil. The proposed new species is supported by a combination of morphological, ultrastructural, and molecular characterization (small subunit ribosomal DNA). Thirteen specimens of A. piracicabae were analyzed and 30.8% was infected by Myxobolus parodontidis n. sp. The myxospores was classified as intralamellar asymmetric type. A few aberrant myxospores with three polar capsules were observed: the spore length and width were the same of normal myxospores, but the polar capsules had smaller sizes. Ultrastructural analysis showed that the plasmodial membrane of Myxobolus parodontidis n. sp. was in direct contact with the host tissue and a connective capsule surrounding the plasmodium was not observed. The phylogenetic analysis showed that the main influence in the clustering of species of myxobolids seems to be related to the phylogenetic relationships established among fish hosts, mainly at the level of family and order. This is the first record of a myxozoan species parasitizing parodontid fish, contributing to the knowledge of the biodiversity of myxozoans from Brazil. [Display omitted] • A new species of Myxobolus is described. • The first record of a myxozoan species parasitizing Parodontidae fish. • Morphological, ultrastructural and molecular data of the new species are provided. • Aberrant myxospores with three polar capsules were observed. • Phylogenetic relationships among fish hosts influenced the phylogeny of myxobolids. [ABSTRACT FROM AUTHOR]

The present study describes three new species of monogenean parasites of characid fishes from the Upper Paraná River basin, Brazil: Characithecium paranapanemense n. sp. on Psalidodon paranae and Psalidodon bockmanni , Diaphorocleidus magnus n. sp. on Astyanax lacustris and Psalidodon fasciatus , and Diaphorocleidus neotropicalis n. sp. on Astyanax lacustris and P. bockmanni. An amendment for Diaphorocleidus is proposed, since additional characters observed in the new species required to extend the generic diagnostic features mainly to include: articulation process connecting the base of the MCO with accessory piece present or absent, and accessory piece with variable shapes (plate-like, pincer-shaped, wrench-shaped, sheath-shaped), divided or not into subunits. Characithecium paranapanemense n. sp. can be distinguished from other congeners by the morphology of its MCO and accessory piece. Diaphorocleidus magnus n. sp. differs from most of its congeners by the morphology of its accessory piece, the presence of articulation process connecting the base of the MCO with accessory piece, and the morphology of the sclerotized structures of the haptor. Diaphorocleidus neotropicalis n. sp. can be easily distinguished from its congeners by the morphology of the accessory piece, the sclerotized structures of the haptor and the morphology of the vagina. Molecular data of the new species (partial 28S rDNA and mitochondrial cytochrome oxidase I) were obtained and the first phylogenetic analysis based on 28S rDNA gene sequences for species of Characithecium and Diaphorocleidus are provided. Although Diaphorocleidus and Characithecium share some morphological similarities, phylogenetic analysis indicates that species of these two genera are not closely related. [Display omitted] • Two new species of Diaphorocleidus and one of Characithecium are described. • Morphological and molecular data of new species are provided. • An amendment to the genus Diaphorocleidus is proposed. • First phylogenetic analysis for Diaphorocleidus and Characithecium are provided. • Phylogeny revealed that Diaphorocleidus and Characithecium are not closely related. [ABSTRACT FROM AUTHOR]

Myxozoans are microscopic cnidarians that mainly parasitize fishes. The present study aimed to describe a new myxozoan parasite from the gills of Boulengerella cuvieri (Spix and Agassiz, 1829) by morphological and molecular analysis. The fish was collected in 2019 at the Pindaíba River, municipality of Cocalinho, Mato Grosso State, Brazil. Whitish and circular plasmodia were found in the primary gill filaments, occupying an intralamellar position, with an average of 0.5 mm in diameter. Henneguya Thélohan, 1892 myxospores found inside the plasmodia were elongated and ellipsoidal, consisting of two long and elliptical shell valves with two long, tapering caudal appendages. Morphometric measurements revealed a total spore length of 36.1 ± 2.0 μm; spore body length of 12.8 ± 0.5 μm; spore width of 4.9 ± 0.3 μm; tail length of 23.3 ± 1.6 μm; capsule length of 7.2 ± 0.4 μm; capsule width of 1.5 ± 0.2 μm; and 10 coils in the polar filament. Phylogenetic analysis showed that the isolates from this study were grouped into the main-clade of freshwater fishes, within a group of species parasitizing fishes from Brazil. Intergenotypic difference ranged from 23%–25.9% compared with other Brazilian myxozoan isolates. Using molecular and morphological characterization, this parasite was identified as a new species of the genus Henneguya. [ABSTRACT FROM AUTHOR]

Piaractus brachypomus (Pacú) is the main native fish species cultivated in Peru and holds great potential for growth in aquaculture from the Peruvian Amazon. Between October 2021 and January 2022 in two fish producing farms in the Amazon region of San Martín in Peru, P. brachypomus individuals were examined for parasite evaluation. A total of 6366 monogeneans were isolated from the gills of 30 fish, revealing a prevalence of 100%, with an abundance and mean intensity of 212 parasites per fish. Monogeneans were morphologically identified as Mymarothecium viatorum and Anacanthorus penilabiatus. The genetic divergence in the 28S rDNA gene found among A. penilabiatus sequences was 0.1% and among Anacanthorus spp. it ranged from 0.9% to 7.5%. The genetic divergence found among the M. viatorum sequences was 0.3%. These finding represents the first molecular data of M. viatorum and A. penilabiatus in Peru using the 28S rDNA gene of these monogeneans. The new sequences obtained will contribute to future studies on the phylogenetic relationships among dactylogyrids. However, further research with a broader range of host-parasite samples and additional genetic markers is needed to clarify these relationships and provide stronger support for the phylogenetic positions., Competing Interests: Declaration of competing interest The authors of the manuscript “Molecular Identification of Mymarothecium viatorum and Anacanthorus penilabiatus in Extensive Native Fish Farming Systems of the Peruvian Amazon” declare that this information has not been previously published, has not been submitted to another journal for publication, and the publication of this manuscript is approved by all authors and by the institutions linked in this document. If the manuscript is accepted for publication it will not be considered for republication in any modified version., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

The recent discovery of disease caused by Nucleospora braziliensis in Nile tilapia (Oreochromis niloticus) is important as it has highlighted the high prevalence of infection and associated mortality in cultured fish. Thus, this study conducted an experimental infection of this microsporidium to evaluate pathological alterations and conduct proteomic analysis. For pathological observation, samples of brain, eyes, gall bladder, gut, heart, kidney, liver, muscle, skin, spleen, and stomach tissue, were collected, and liquid chromatography-mass spectrometry (LC-MS/MS) was performed for proteomic analysis. The most prevalent lesions were brownish color of the liver, gill filament fusion, gut ischemia, hemorrhage of the lips and fins, hepatomegaly, spleen atrophy, splenomegaly, and stomach congestion. The most common microscopic lesions were degeneration, hemorrhage, and inflammation in the brain, gills, gut, kidney, liver, muscle, spleen, and stomach. The digested peptides were identified by LC-MS/MS and the intersection of each group showed that in the spleen there were 121 exclusive proteins in the infected sample and 252 in the control, while in the kidney, 129 proteins were identified in the infected specimen compared to 83 in the control. In conclusion, this study demonstrates the proteome profile of O. niloticus kidney and spleen tissue in response to infection with N. braziliensis., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Background: Allocreadiids are relatively small digeneans that appear to be restricted to freshwater systems distributed across the world. Allocreadiids are highly diverse in the Americas, particularly in the Neotropical biogeographical region. Their taxonomic history has been rather controversial, with several taxonomic reassessments and the description of new genera and species., Methods: We sampled Creptotrematina specimens from a characid collected in the Pardo River, Paranapanema River basin in Brazil, and specimens of C. aguirrepequenoi, from Astyanax spp. in several localities between northern Mexico and Costa Rica. The specimens were studied through integrative approaches using morphological and molecular analyses of the 28S rDNA gene and two different regions of the COI mtDNA gene., Results: We describe a new species of Creptotrematina which is differentiated from other congeners by the overall body size, but in particular by the size and position of the cirrus-sac, distribution of the vitelline follicles, and extension of uterine loops in the posterior end of body. Phylogenetic analyses of the 28S rDNA and COI mtDNA genes placed the new species in a monophyletic clade together with all other sequenced species of Creptotrematina, and as a sister species of C. batalhensis. Genetic divergences between the new species and other Creptotrematina spp. varied from 1.1 to 1.2% for the 28S rDNA and 12.4-14.3% for the COI mtDNA. Phylogenetic analysis based on COI mtDNA showed the isolates of C. aguirrepequenoi grouped in four monophyletic clades representing populations geographically separated along a wide geographical range spanning between northern Mexico and Costa Rica, with an estimated genetic divergence between 3.9% and 8.9%., Conclusions: Our findings based on integrative analyses recognize Creptotrematina saltograndensis n. sp. from a characid collected in the Pardo River, Paranapanema River basin in Brazil and provide validation of the wide geographical distribution of C. aguirrepequenoi across Middle-America parasitizing Astyanax spp.; the genetic divergence of the species through the analysis of two regions of COI mtDNA points towards considering it represent a species complex, although we refrain at the moment on describing a new species, awaiting for further verification using other molecular markers, and obtaining fresh material for a more detailed taxonomic analyses. This study increases the known diversity of allocreadiids and contributes to the understanding of evolutionary relationships, host-parasite relationships, and biogeographic history of the group., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Species of Haemogregarina are blood parasites known to parasitise vertebrate hosts, including fishes (Haemogregarina sensu lato) and freshwater turtles (Haemogregarina sensu stricto). Their vectors, include gnathiid isopods and leeches, respectively. In turtles, Haemogregarina balli has the best-characterized life cycle in the genus. However, no studies in Brazil have suggested a possible vector for any species of Haemogregarina from freshwater turtles. Therefore, in the present study, we provide insights into a leech vector based on specimens found feeding on two species of freshwater turtles, Podocnemis unifilis and Podocnemis expansa, using morphological and molecular data. In 2017 and 2019, freshwater turtles were collected in Goiás State, Brazil. Hosts were inspected for ectoparasites and leeches were collected from two specimens of P. expansa and nine specimens of P. unifilis. Leeches were subsequently identified as members of the genus Unoculubranchiobdella. Leech histological slides revealed haemogregarine-like structures, similar to post-sporogonic merogony, found near the gills and within the posterior sucker. Molecular analysis of the haemeogregarines resulted in the identification of three species of Haemogregarina: Haemogregarina embaubali, Haemogregarina goianensis, and Haemogregarina brasiliana. Therefore, our findings, based on morphology and DNA data suggest leeches of the genus Unoculubranchiondella as vectors for at least three species of Haemogregarina from Brazilian turtles., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

In the present study, we examined 30 individuals of introduced African cichlids, Oreochromis niloticus and Coptodon rendalli, collected in a river spring of the Pardo River, Paranapanema River basin, southeastern Brazil. Based on morphological and molecular analyses of the partial LSU rDNA gene, we identified four species of monogeneans, Cichlidogyrus tilapiae, C. thurstonae, C. mbirizei, and Scutogyrus longicornis on the gills of O. niloticus, whereas individuals of C. rendalli were infested only with C. papernastrema. This is the first record of C. mbirizei and C. papernastrema in tilapias from Brazil. The ecological consequences of the introduction of exotic species of tilapia such as O. niloticus and C. rendalli along with their monogenean parasites in a wild environment represented by a river spring are discussed. Our new molecular data on Cichlidogyrus and Scutogyrus contribute to the investigation of the phylogenetic interrelationships of these widely distributed genera of monogeneans since their species composition is still unsettled., (© M.B. Ebert et al., published by EDP Sciences, 2024.)

The dactylogyrid genus Rhinoxenus (Monogenea: Dactylogyridae) is composed of specialized monogeneans infecting the nasal cavities of freshwater fishes from the Neotropical region. This taxon currently comprises 11 species and is easily distinguished from other monogeneans by the absence of the dorsal bar, ventral anchor with inconspicuous roots covered by a sclerotized cap, dorsal anchor greatly modified into a needle-like shape, and hook pair 2 located into bilateral lobes of the trunk. Specimens of Rhinoxenus euryxenus and Rhinoxenus paranaensis were found infecting the nasal cavities of Serrasalmus marginatus and Serrasalmus maculatus, respectively, from the Paraná River basin in Brazil. For the first time, molecular data of Rhinoxenus spp. were obtained and used as a basis for phylogenetic analyses of the genus. Furthermore, our findings represent the first record of R. paranaensis in Brazil., (© 2023. The Author(s), under exclusive licence to Springer Nature B.V.)

Purpose: Brazilian anurans are considered the most diverse and species rich around the world. Although in recent years there has been a strong focus on research related to this group of animals, their parasites have not received the same attention. Thus, this study aimed to provide morphological and molecular data on haemogregarines biodiversity infecting Brazilian anurans., Methods: During 2020, 116 anurans were collected from four Brazilian States and their blood and fragment of organs were screened for haemogregarine parasites., Results: From the total, seven (6.03%) animals were found infected with species of Hepatozoon and Dactylosoma. Based on the morphological and molecular analysis, four anurans were found infected with Hepatozoon latrensis. The phylogenetic analysis has shown the isolates from this study grouping with the Brazilian anuran Hepatozoon clade, also with gene similarity ranging from 99.70 to 100% to H. latrensis isolates available on GenBank. Furthermore, three specimens (Trachycephalus typhonius, Leptodactylus latrans, and Rhinella diptycha) were infected with the same species of Dactylosoma (100% genetic similarity), with a genetic similarity of 98.56% to Dactylosoma piperis the only other species described in Brazil. In support of the molecular data, different morphological characters were observed in the blood smears as compared to D. piperis, suggesting that the species of Dactylosoma from the present study infecting three different species of Brazilian anurans is an undescribed species., Conclusion: Thus, this study increases the knowledge of Brazilian anuran blood parasites and demonstrates the importance of using integrative approaches for the diagnosis of haemoparasites., (© 2022. The Author(s) under exclusive licence to Witold Stefański Institute of Parasitology, Polish Academy of Sciences.)

A new parasitic copepod, Tiddergasilus bipartitus n. sp. (Copepoda, Ergasilidae), is described herein based on three adult females found attached to the gills of the yellow-tail lambari Astyanax lacustris (Lütken), sampled in Pardo River, municipality of Botucatu, São Paulo State, Brazil. Tiddergasilus bipartitus n. sp. was recognized as a new member of the monotypic genus Tiddergasilus Marques & Boeger, 2018 by having: antennule 6-segmented; maxillary basis armed with 2 terminal teeth and ornamented with multiple spinules; second and third leg both with endopod 3-segmented. The new copepod can be distinguished from its congener, Tiddergasilus iheringi (Tidd, 1942), by the morphology of the antennal claw, number of somites/segments in abdomen and fourth leg, and by the ornamentation of the first leg. This report expands the geographic distribution and diversity of fish species parasitized with Tiddergasilus spp. in Brazil. Moreover, it also represents the first report of an ergasilid species in the Pardo River. A list of diagnostic features for the Brazilian species of Ergasilus von Nordmann, 1832 is provided herein, in order to aid comparisons with the species of this complex genus., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

Rhamdia quelen is a commercially important fish in South America. During the survey of myxozoan infections in fishes from Pardo River, Paranapanema River basin, São Paulo State, Brazil, we describe three new species of Henneguya found parasitizing gills of R. quelen: Henneguya bagre n. sp., Henneguya breviscauda n. sp and Henneguya novaerae n. sp. The descriptions were based on myxospores morphology and small subunit ribosomal DNA partial sequences. Phylogenetic analysis showed a clade formed by species that parasitize Siluriformes, with Henneguya jundiai as a sister species of Henneguya bagre n. sp., Henneguya breviscauda n. sp and Henneguya novaerae n. sp. Our study indicates that the parasites infecting R. quelen belong to a lineage of myxozoans infecting Heptapteridae fishes. Using molecular and morphological characterization, the species were identified as new species for the genus Henneguya. Based on our analysis we recommend monitoring the presence of these parasites in farmed fishes, to analyze possible pathologies caused by them., (© 2022. The Author(s).)

Purpose: We describe two new species of Myxobolus (Myxobolidae) found parasitizing Mugil curema from two locations in Brazil: Myxobolus curemae n. sp. from gill arch and rays and Myxobolus maceioensis n. sp. from gill lamellae., Methods: We based the descriptions on myxospore morphology, histology, and small-subunit ribosomal DNA sequences., Results: Myxospores of the two new species had similar morphology and morphometry but differed in spore body width and length, and ssrDNA sequences differed by 10.5%. These data supported the diagnosis of the parasites as distinct and novel species. The phylogenetic analysis showed a subclade formed by species that parasitize Mugiliformes, with M. maceioensis n. sp. as a sister species of Myxobolus episquamalis and Myxobolus bizerti, while there is a group of six species that are sister related to M. curemae n. sp. Our analysis was consistent with previous studies suggesting that orders of the hosts are strongly correlated with phylogenetic signals in the Myxobolidae., Conclusions: Myxobolus curemae n. sp. and M. maceioensis n. sp. are new species identified parasitizing M. curema., (© 2022. The Author(s) under exclusive licence to Witold Stefański Institute of Parasitology, Polish Academy of Sciences.)

We describe Myxobolus cataractae n. sp., found parasitizing Imparfinis mirini from Cachoeirinha stream, a tributary of Pardo River, Paraná River basin, municipality of Botucatu, São Paulo State, Brazil. We based the description on myxospore morphology, histology, and small subunit ribosomal DNA partial sequences. Whitish and elongated mass of myxospores were found in gill filaments, occupying an intrafilamental position. The myxospores were slightly ellipsoidal and the morphometric measurements revealed a myxospore body length of 7.8 ± 0.4 μm; myxospore width of 5.9 ± 0.4 μm; and thickness of 3.9 ± 0.3 μm. The polar capsules are equal in size and measured 3.5 ± 0.2 μm in length and 1.7 ± 0.2 μm in width. The polar tubules had 6-7 coils. Myxobolus cataractae n. sp. is classified as the intrafilamental type and chondreal subtype by the histological analysis of gills. Phylogenetic analysis showed a well-supported subclade formed by species that parasitize gills of Siluriformes, with M. imparfinis as a sister species of Myxobolus cataractae n. sp. Using molecular and morphological characterization, this cryptic species was identified as a new species of the genus Myxobolus., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Purpose: We describe two new Henneguya spp. (Myxobolidae) found parasitizing Cyphocharax modestus from Pardo river, Paraná river basin, municipality of Botucatu, São Paulo State, Brazil: Henneguya fastigata n. sp. from gill lamellae and Henneguya pardensis n. sp. from gill arches. We based the descriptions on myxospore morphology, histology, and small subunit ribosomal DNA sequences., Methods: In this investigation, 50 specimens of Cyphocharax modestus were examined between July and December 2020 for myxozoan infections. Morphological characterization was based on the mature myxospores. The small subunit ribosomal DNA sequences were used for molecular and phylogenetic study., Results: Phylogenetic analysis provided the evolutionary position of these new species with other myxobolids species. Myxospores of the two species had similar morphology and morphometrics, but differed in spore body width and length, and ssrDNA sequences differed by 7.2%. These data supported the diagnosis of the parasites as distinct and novel species. The phylogenetic analysis showed a well-supported subclade formed by species that parasitize curimatid fishes, with Henneguya gilbert as a sister species of Henneguya fastigata n. sp., and Henneguya pardensis n. sp. as a sister species of both species., Conclusion: Our analysis was consistent with previous studies suggesting that orders and families of the hosts are strongly correlated with phylogenetic signals in the Myxobolidae. These are the first species of myxozoans described in the Pardo river., (© 2021. Witold Stefański Institute of Parasitology, Polish Academy of Sciences.)

Purpose: To date, seven species of Characithecium Mendonza-Franco, Reina and Torchin, 2009 (Monogenea, Dactylogyridae) are valid, parasitizing mainly fishes of the family Characidae (Characiformes) in the Neotropical region. During a parasitological study of fishes in the Batateiras River and Carás stream, Ceará state, Brazil, two species of Characithecium were collected from the gills of Astyanax bimaculatus Linnaeus, 1758 (Characidae). The purpose of the present study is to describe a new species of monogenean of the genus Characithecium and report Characithecium costaricensis Mendoza-Franco, Reina and Torchin, 2009 in A. bimaculatus, in Brazil., Methods: Monogeneans were isolated from the gills and stored in 70% ethanol, mounted in Gray and Wess' medium or and in a mixture of glycerin ammonium picrate (GAP) to study sclerotized structures. Morphological analyses were performed with a computerized image analysis system with differential interference contrast (DIC). The drawings were obtained with the aid of a camera lucida mounted on a Leica DMLS microscope., Results: Characithecium bifurcuprolatum n. sp. differs from its congenerics by the morphology of the accessory piece having a ventral unit articulated to cirrus base, a non-articulated dorsal and mid-ventral, and a sclerotized vaginal vestibule. Characithecium costaricensis was described from Astyanax aeneus (Günther, 1860) (Characidae) in Central America, and the present finding represents a new geographical and host records in Brazil. Furthermore, we observed the presence of a membrane at the base of the cirrus not mentioned in the original description., Conclusion: Our findings increase to eight the number of known species of the genus Characithecium parasitizing characids in neotropics. We verified some additional characteristics present in the two species studied, such as the presence of a membrane at the base of the cirrus, an accessory piece with two subunits (an articulated ventral and a dorsal non-articulated) and the presence of sclerotized vaginal vestibule., (© 2021. Witold Stefański Institute of Parasitology, Polish Academy of Sciences.)

Purpose: Species of Hepatozoon Miller, 1908 (Hepatozoidae) are blood protozoans with a cosmopolitan distribution and are reported to parasitize a range of vertebrate hosts including mammals, birds, reptiles, and amphibians. The present study aimed to describe a new species of Hepatozoon (Apicomplexa: Adeleorina: Hepatozoidae) found infecting the sleep snake Dipsas mikanii (Schlegel, 1837) (Squamata: Colubridae: Dipsadinae)., Methods: The snake was collected in 2017 at the municipality of Britânia, Goiás State, Brazil. Blood smears were made in order to find blood gametocytes and PCR was performed targeting the 18S rRNA gene., Results: Microscopy screening of blood smears revealed the presence of intraerythrocytic gamont stages of Hepatozoon sp. in the peripheral blood with a parasitemia of 0.25%. Furthermore, meronts and monozoic cysts were observed in histological sections of the liver from the infected individual. The interspecific divergence of 18S rRNA sequences fragments isolated from D. mikanii had differences (2.39-11.3%) as compared to other sequences of species of Hepatozoon from snakes., Conclusions: Based on morphological and molecular data, a new species of Hepatozoon infecting D. mikanii from Brazil is described., (© 2021. Witold Stefański Institute of Parasitology, Polish Academy of Sciences.)

Emerging infectious diseases in wild animals related to humans have received greater attention in recent years. Mycobacteriosis is a bacterial disease of animal and human importance. Mycobacterium gordonae infects the skin and internal organs of free-ranging amphibians and is considered the least pathogenic member of the Mycobacteriaceae to humans. However, information about its infection and pathogenesis in wild amphibians is still lacking. A total of 1306 amphibian specimens belonging to 6 families, 12 genera, and 21 species were collected and dissected during a helminthological survey of 7 municipalities in southern Ceará state, Caatinga (eco)region, northeast Brazil. Of these, 17 specimens (0.76%), belonging to 2 families and 4 species (Leptodactylus macrosternum, n = 2; L. vastus, n = 10; Pseudopaludicola pocoto, n = 2; Rhinella jimi, n = 3), presented infections that consisted of calcification nodules in the coelomic cavity, kidney, liver, lung, gut, and pancreas. The nodules were examined by histopathology and PCR. The bacteria were identified as M. gordonae by molecular analyses. Infected animals presented with hepatocellular vacuolar degeneration, karyolysis, and karyorrhexis, hepatic portal congestion, hemorrhage, mononuclear cellular infiltration, melanomacrophage center hyperplasia, and granulomas in varying stages of development with intralesional acid-fast bacilli. This study is the first report of M. gordonae in these amphibian species, in which results of molecular analyses confirmed the presence of M. gordonae in natural environments and histopathology confirmed the typical lesion of mycobacteriosis in amphibians from northeastern Brazil.

Purpose: To describe three new species of Cosmetocleithrum in the gills of Trachelyopterus galeatus (Siluriformes, Auchenipteridae) from Aguapeí River, Upper Paraná River basin, São Paulo State, Brazil., Methods: Fifty-three specimens of T. galeatus were captured in the mouth of the Aguapeí River from August 2013 to June 2014. Monogeneans were mounted unstained in Hoyer's and Gray and Wess's medium., Results: Cosmetocleithrum spathulatum sp. n., Cosmetocleithrum baculum sp. n., and Cosmetocleithrum galeatum sp. n. differ from all known congeneric species mainly in the morphology of the accessory piece (i.e. spatulate-shaped, claviform, and a straight rod with hook-shaped distal portion, respectively). Also, the three new species share hooks with different sizes with hooks pairs 5 and 7 bigger than others and with an erect delicate point, inconspicuous thumb, longer shaft, and slender shank., Conclusions: To date, 18 species of Cosmetocleithrum were recognised parasitizing siluriforms in the Neotropical region. The present study expands the number to 21 species, however, despite this increase, the number of known taxa of monogeneans in neotropics is far from representing the ideal situation.

Two digenean species, Infidum infidum Faria, 1910 (Dicrocoeliidae) and Travtrema stenocotyle Cohn, 1902 (Plagiorchiidae), were collected in the large pit viper Bothrops moojeni Hoge, 1966 from Reserva Particular do Patrimônio Natural Cisalpina, municipality of Brasilândia, Mato Grosso do Sul State, Brazil. In this study, we provide the first molecular characterisation using the 28S rDNA and phylogenetic position data of these two common digeneans from B. moojeni. The molecular framework revealed topologies with strongly supported clades using maximum likelihood and Bayesian inference methods, positioned I. infidum among Plagiorchiidae and not among Dicrocoeliidae as expected and T. stenocotyle (Plagiorchiidae) surprisingly grouped as a sister group to Allassogonoporidae, Microphallidae, Pleurogenidae, and Prosthogonimidae, not related to plagiorchids. Our molecular phylogenetic data showed that these species may not correspond to their assigned families and encourage future studies on the systematic of these understudied groups.

Purpose: To describe, based on morphological features, a new copepod species of Rhinergasilus, Rhinergasilus unguilongus n. sp., collected from gills of the Streaked prochilod, Prochilodus lineatus (Valenciennes, 1837), sampled in the Veados and Paranapanema Rivers, two tributaries of the Jurumirim Reservoir (Upper Paranapanema River, Paraná River Basin), São Paulo State, Brazil., Methods: Fish were collected using multi-panel gill nets. The gills of each fish were washed and examined for copepods using a stereo microscope. The copepods found were stored in 70% ethanol, cleared in lactic acid, and mounted in Hoyer's medium. Drawings were made with the aid of a microscope equipped with a drawing tube., Results: The new copepod species can be distinguished from its two congeners, Rhinergasilus piranhus (type-species) Boeger et Thatcher, 1988 and Rhinergasilus digitus Narciso, Brandão, Perbiche-Neves et Silva, 2020, due to its extremely long antennary claw (etymology of the species), being longer than the other antennary segments; third leg lacking any interpodal plate; and third endopodal segment of third leg lacking a distal spine., Conclusions: Based on the morphological differences, we erected a new species of Rhinergasilus. The new copepod represents the second report of a Rhinergasilus species parasitizing a fish from the Jurumirim Reservoir. It also represents the first report of this genus in P. lineatus.

Wallinia caririensis n. sp. is described from the intestine of Astyanax bimaculatus (Linnaeus, 1758) (Characidae) collected in the Batateiras River in the municipality of Crato, Ceará state, Brazil. The description was based on integrative taxonomy approach using DNA sequences from the D1-D3 domains of the 28S rDNA gene. The new species was confirmed through the phylogenetic analysis of the 28S rDNA gene, which showed that Wallinia caririensis n. sp. is a sister taxon of Wallinia brasiliensis (Dias, Müller, Almeida, Silva, Azevedo, Pérez-Ponce de León, and Abdallah, 2018, and Wallinia anindoi Hernández-Mena, Pinacho-Pinacho, García-Varela, Mendonza-Garfias, and Pérez-Ponce de León, 2019), a species which parasitizes Astyanax fasciatus (Cuvier, 1819), A. lacustris (Lucena and Soares, 2016) in Brazil, and A. aeneus (Günther, 1860) in Mexico, with genetic divergences of 2% and 3%, respectively. The new species can be distinguished morphologically from its congeners by possessing large body size (length and width) and tapered extremity in the posterior end of the body, eyespots are present at the pharynx level, and vitelline follicles reach up to the half distance between the posterior testis and the extremity of the body, by having larger testes distributed in coincident zones (i.e., contiguous) and non-operculated eggs (a conspicuous characteristic in W. brasiliensis). To date, species of this genus have already been described in freshwater fishes from Mexico, Costa Rica, Venezuela, and Southeastern Brazil. The species described in this study consists of the second species parasitizing characids in Brazil, and the first record in Northeastern Brazil. This finding fills a gap and expands the biogeographic distribution of the genus Wallinia in South America.

Diversity of Creptotrema was investigated using morphological and molecular tools, including data for Creptotrema creptotrema (type-species). Three new species, parasites of Brazilian fishes, are described: Creptotrema conconae n. sp. (type-host, Imparfinis mirini Haseman), Creptotrema schubarti n. sp. (type-host, Characidium schubarti Travassos) and Creptotrema megacetabularis n. sp. (type-host, Auchenipterus osteomystax (Miranda Ribeiro)). The diagnosis of the genus was amended to include new features. The new species differ from each other mainly in terms of body shape, relative sucker size, and testes position. DNA sequences were obtained from Creptotrema spp. from Brazil, including 28S, ITS and COI. Genetic divergences among the new species and C. creptotrema varied from 2.1 to 5.2% (21-49 bp) for 28S, and 6.6 to 16.4% (21-45 bp) for COI. Phylogenetic analysis (28S) placed the newly generated DNA sequences of Creptotrema in a clade (Creptotrema clade sensu stricto) composed of C. creptotrema, the new species described herein, and all species previously described as Auriculostoma, revealing that Auriculostoma is best interpreted as a synonym of Creptotrema based on the principle of priority of zoological nomenclature. Creptotrema funduli, the single sequence of the genus previously available, was not grouped within the Creptotrema clade sensu stricto, suggesting the need for reevaluation of the taxonomic status of this species. Our results showed that Creptotrema represents a monophyletic genus of trematodes widely distributed across the Americas, which currently comprises 19 valid species of parasites of teleosts and anurans., (© L. Franceschini et al., published by EDP Sciences, 2021.)

We report for the first time the infection of dolphins with Ascocotyle longa found in the intestines of three different species, Sotalia guianensis, Steno bredanensis, and Tursiops truncatus gephyreus, which were found washed ashore along the southeastern and southern Brazilian coast. The worms were identified based on morphological and molecular data using the 28S rDNA gene and the COI gene. Specimens of A. longa from the pinniped Otaria flavescens were also analyzed. As the first isolation of A. longa from cetaceans, the present study increases the distribution area and range of definitive hosts of this trematode, and provides new molecular data to complement the phylogeny of the group in future studies, thus contributing to the scientific knowledge of this potentially zoonotic parasite.

Seven new species of Urocleidoides from the gills and skin of nine Neotropical fish hosts (Anostomidae, Parodontidae, and Gymnotidae) are described: Urocleidoides digitabulum n. sp. on Leporinus friderici, Leporinus octofasciatus, and Megaleporinus elongatus (Anostomidae); Urocleidoides solarivaginatus n. sp. on L. friderici, L. octofasciatus, and Leporinus striatus (Anostomidae); Urocleidoides falxus n. sp. and Urocleidoides sapucaiensis n. sp. on M. elongatus; Urocleidoides tenuis n. sp. on Apareiodon piracicabae and Apareiodon affinis (Parodontidae); Urocleidoides sinus n. sp. on L. striatus, Schizodon nasutus, and Schizodon intermedius (Anostomidae); and Urocleidoides uncinus n. sp. on Gymnotus sylvius (Gymnotidae). Urocleidoides paradoxus was also found in this study on L. friderici and included in the phylogenetic analysis. Molecular data (partial 28S rDNA and mitochondrial cytochrome oxidase subunit I) were obtained for U. digitabulum n. sp., U. tenuis n. sp., U. sinus n. sp., and U. uncinus n. sp. The identification of Urocleidoides is amended herein to include all taxonomic modifications observed in this genus over time and add new characteristics observed in the species in the present study. Phylogenetic analysis revealed Urocleidoides digitabulum n. sp. and Urocleidoides sinus n. sp. (parasites of anostomids) closely related in the tree topologies. Furthermore, the new species described herein parasitized phylogenetically distant host species (Characiformes and Gymnotiformes), suggesting the effect of the dynamic process of ecological fitting.

We investigated the mean abundance of helminths and analyzed helminth composition and structure at the infracommunity and component community levels for 3 anuran species (Pleurodema diplolister, Rhinella jimi, and Rhinella granulosa) from the Caatingas, a semiarid Brazilian region characterized by accentuated seasonality and unpredictability of rains. Data were collected during the reproductive period and during drought, when P. diplolister estivated buried underground but R. jimi and R. granulosa remained foraging actively. We expected higher parasitological parameters during the reproductive period when compared to drought for these 3 anurans. We also expected higher parasite infection in the Rhinella species and higher similarity between their helminth parasite communities when compared to the estivating species, P. diplolister. Contrary to our hypothesis, the season was not related to parasite community structure. As predicted, the Rhinella toads shared more similar species composition of parasite communities. These similarities in the composition of the parasite community between Rhinella species could be due to similar temporal/spatial patterns of activity and phylogenetic proximity. Pleurodema diplolister hosted a more restricted helminth fauna, a result that might be associated with estivation restricting the temporal window available to acquire parasites. This study also presents new helminth fauna records for R. jimi and P. diplolister, and the first helminth fauna record of R. granulosa from the Caatingas in semiarid Brazil., (© American Society of Parasitologists 2020.)

Purpose: To describe a new species of a parasitic copepod, Rhinergasilus digitus n. sp. (Cyclopoida, Ergasilidae), collected from the gills of the red-tailed lambari Astyanax fasciatus (Characiformes, Characidae) in two tributaries of the Jurumirim Reservoir (Upper Paranapanema River), São Paulo State, Brazil: Ribeirão dos Veados and Paranapanema River., Methods: Fish were collected using multi-panel gills nets. The gill of each fish was washed and examined in a stereo microscope for copepods. The copepods found were stored in 70% ethanol, cleared in lactic acid, and mounted in Hoyer's medium. Drawings were made with the aid of a Leica microscope DMLS equipped with a drawing tube., Results: The new species differs from its congeneric species, Rhinergasilus piranhus (type-species), in having comparatively biggest body size (body length: 535-598 µm in the new species vs. 237-282 µm in R. piranhus); second antennary segment armed with a minute sensillum near middle of inner margin and a row of spinules on outer margin; third exopodal segment of leg 1 with digitiform process; interpodal plates two and three both ornamented with spinules along posterior margin; leg 5 reduced and represented by two unequal setae., Conclusions: Based on the morphological differences described above, we erected a new species of Rhinergasilus. Rhinergasilus digitus n. sp. is the second ergasilid described from A. fasciatus, as well as it represents the first report of this genus in a characid fish.

The Dactylosomatidae Jakowska and Negrelli, 1955 are one of four families belonging to adeleorinid coccidia and comprise the genera Babesiosoma Jakowska and Nigrelli, 1956 and Dactylosoma Labbé, 1894. These blood protozoa occur in peripheral blood of lower vertebrates, and are commonly reported parasitising amphibians. The present study describes Dactylosoma piperis n. sp. from the pepper frog Leptodactylus labyrinthicus (Spix, 1824) (Anura: Leptodactylidae), collected in 2018 at the municipality of Araguaiana, Mato Grosso State, Brazil, based on morphology of intra-erythrocytic trophozoite, primary and secondary merogonic stages and a molecular analysis (partial 18S rDNA). Dactylosoma piperis n. sp. forms a well-supported clade with other Dactylosomatidae. This is the first molecular characterization of a species of Dactylosoma from a Brazilian anuran., (© L.P. Úngari et al., published by EDP Sciences, 2020.)

Purpose: To describe a new genus and a new species of an ectoparasitic ergasilid (Copepoda, Ergasilidae) parasite of the red-tailed lambari, Astyanax fasciatus, from Jurumirim Reservoir (Upper Paranapanema River), São Paulo State, Brazil., Methods: The host fish were collected using multi-panel gill nets. The gill of each fish was washed and examined in a stereo microscope for copepods. The copepods found were stored in 70% ethanol, cleared in lactic acid, and mounted in Hoyer's medium. Some specimens were dissected in glycerol medium and then each dissected part was mounted on individual slides., Results: A new genus and a new species of Ergasilidae were described herein. Duoergasilus basilongus n. gen., n. sp. differs from all other ergasilids in having the second and third pair of biramous swimming legs (P2 and P3) each with a 2-segmented endopod, and by its unique maxillary basis, resembling a whip., Conclusions: The new copepod is the first 'four-legged' ergasilid with all swimming legs having a 2-segmented endopod. Duoergasilus basilongus n. sp. represents the first record of a parasitic copepod on A. fasciatus in Jurumirim Reservoir, as well as its represents the first description to species level of an ergasilid infecting an Astyanax species in Brazil. A key to the 28 accepted genera of Ergasilidae is provided.

On the basis of morphological and molecular analyses, a new myxozoan parasite is described from the gills of the fish Hoplerythrinus unitaeniatus, collected in the municipality of Nova Xavantina, Mato Grosso State, Brazil. Plasmodia of Henneguya unitaeniata sp. nov. were oval and whitish and were found surrounded by collagen fibers forming plasmodia wall between gill filaments on the gill arch. The spores were ellipsoidal with two similar polar capsules. Morphometric analysis showed a total spore mean length of 23.8 ± 1.5 μm, spore body mean length of 14.5 ± 0.7 μm, caudal appendage mean length of 10.3 ± 1.4 μm, thickness mean length of 4.3 ± 0.3 μm, polar capsule mean length of 4.2 ± 0.5 μm, polar capsule mean width of 1.8 ± 0.3 μm, spore mean width of 4.8 ± 0.4 μm, and 4-5 polar filament coils. Phylogenetic analysis showed Henneguya unitaeniata sp. nov. as a basal species in a subclade formed by myxozoans that parasitize bryconid fishes.

The Diplostomidae include a large group of flatworms with complex life cycles and are frequently found parasitizing the eyes and central nervous system of freshwater fishes. The morphological identification of the metacercariae at species level is not always possible. Thus, molecular tools have become essential to assist in the parasite species determination. This study was aimed at describing two diplostomid metacercariae found in freshwater fish in São Paulo, Brazil, based on morphological characters and in the genetic characterization of COI sequences. Our results showed that the two recognized taxa (Tylodelphys sp. and Diplostomidae gen. sp.) appear to be different from the species already described in South America. Tylodelphys sp. differs morphologically from Tylodelphys xenopi, T. mashonense, T. jenynsiae, and T. scheuringi. The metacercariae of T. clavata and T. conifera are smaller than Tylodelphys sp., while T. podicipina is larger than the metacercariae described here. The phylogenetic analysis of COI sequences yielded Tylodelphys sp. as the sister species of Tylodelphys sp. 4, a species reported from the brain of the eleotrid Gobiomorus maculatus in Oaxaca, Mexico. The metacercariae identified as Diplostomidae gen. sp. are morphologically different from the known diplostomid metacercariae and did not match with other diplostomid sequences available. Diplostomidae gen. sp. is recovered as the sister species of Diplostomum ardeae. Although the morphological evidence and the COI sequences differentiate the metacercariae found, the absence of adult specimens of both species precludes the specific designation. This is one of the first papers that use an integrative taxonomy approach to describe the species diversity of diplostomid trematodes in Brazil.

Nematodes belonging to Spinitectus Fourment, 1883 (Nematoda: Cystidicolidae) were found in the intestine of Pimelodella avanhandavae Eigenmann (Siluriformes: Heptapteridae) from the Aguapeí River, Brazil. They represent a new species, Spinitectus aguapeiensis n. sp., which differs morphologically from its congeners in the body length, the number of spinose rings, the location of the excretory pore, the number of precloacal papillae and the length of the spicules. The new species is the first South American species within the genus with a remarkably spirally coiled posterior extremity in males and the largest spicules. It is also the second species with the highest number of precloacal papillae and has unique shape of the small spicule. Spinitectus aguapeiensis n. sp. is the first helminth species found in P. avanhandavae, the fourth species of this genus recorded in the River Paraná Basin and the sixth species of Spinitectus in South America.

A complete morphological description, supported by molecular data, of Clinostomum detruncatum metacercariae is reported in this study. The metacercariae were found infecting Synbranchus marmoratus from the Paraná River, municipality of Guaíra, Paraná State, Brazil. The taenioidean uterus is the main morphological characteristic of this species. Both neighbor-joining (NJ) and maximum likelihood (ML) trees showed 2 clear separate clusters grouping together the species from the Palearctic region (Clinostomum complanatum, Clinostomum cutaneum, Clinostomum phalacrocoracis, Clinostomum philippinense) and those from the Nearctic/Neotropical regions (Clinostomum marginatum, Clinostomum tataxumui, C. detruncatum, Clinostomum sp. 7). The latter clade is divided into 2 subclades grouping species from North America and Mexico (C. marginatum and C. tataxumui), and those from Brazil (C. detruncatum and Clinostomum sp. 7).

The aim of this study was to provide the first report on a new host for the digenean Paratanaisia bragai in the caninde macaw Ara ararauna along with the pathological aspects of the infection in the new host. The microscopic findings revealed the presence of granulomatous interstitial nephritis. This study contributes towards knowledge of parasitism by P. bragai in A. ararauna, and emphasizes the need to use best practices in wildlife conservation parks.

There is an increasing interest in unveiling the dynamics of parasite infection. Understanding the interaction patterns, and determinants of host-parasite association contributes to filling knowledge gaps in both community and disease ecology. Despite being targeted as a relevant group for conservation efforts, determinants of the association of amphibians and their parasites in broad scales are poorly understood. Here we describe parasite biodiversity in South American amphibians, testing the influence of host body size and geographic range in helminth parasites species richness (PSR). We also test whether parasite diversity is related to hosts' phylogenetic diversity. Results showed that nematodes are the most common anuran parasites. Host-parasite network has a nested pattern, with specialist helminth taxa generally associated with hosts that harbour the richest parasite faunas. Host size is positively correlated with helminth fauna richness, but we found no support for the association of host geographic range and PSR. These results remained consistent after correcting for uneven study effort and hosts' phylogenic correlation. However, we found no association between host and parasite diversity, indicating that more diversified anuran clades not necessarily support higher parasite diversity. Overall, considering both the structure and the determinants of PRS in anurans, we conclude that specialist parasites are more likely to be associated with large anurans, which are the ones harbouring higher PSR, and that the lack of association of PSR with hosts' clade diversification suggests it is strongly influenced by ecological and contemporary constrains.

Hepatozoon sp. are parasites that commonly infect frogs and arthropod vectors. This species has variability in the morphological and morphometric characteristics. Due to these variations, the naming of the species is thus impaired and only by visualizing the sporogonic cycle in vector and by molecular studies this problem can be solved. Recently, the use of molecular genetics has helped the species denomination. In this work, we collected 145 frogs (68 Leptodactylus chaquensis and 77 Leptodactylus podicipinus) in different sampling sites, where were found 18 (26.47%) L. chaquensis and 24 (31.17%) L. podicipinus parasitized; besides of gamonts, schizogonic forms were also seen in animals organs. The positivity difference between the collection sites for both frog species was not significant (p = 0.958). Comparing gamonts found in each species of anuran, we observed differences in morphology. The comparison in the molecular level for L. podicipinus was not possible due to small amount of blood obtained, just L. chaquensis had their parasites DNA sequenced. The amplified and sequenced samples, named HEP1 to HEP10, are presented in the phylogenetic tree as a different branch from other haemogregarines described on other hosts. Therefore, we have seen that, although the morphology and morphometry of the collected parasites at each site showed differences, the sequencing of these samples revealed identical species of Hepatozoon, and different compared to those from GenBank, thereby demonstrating that the species of Hepatozoon in L. chaquensis observed in this study probably represent a new species.

Fifty specimens of Cichla piquiti were collected from the Paraná River downstream of the Ilha Solteira Hydroelectric Power Station in Brazil and surveyed for endohelminth parasites. All fish were parasitised by at least one helminth species (overall prevalence [P] = 100%). Eight parasite taxa were present: the nematode Procamallanus (Procamallanus) peraccuratus in the intestines; third-stage larvae of the anisakids Contracaecum sp. and Hysterothylacium sp. in the visceral cavity, mesentery and serosa of the stomach and intestines and on the liver and spleen; the trematodes Austrodiplostomum compactum in the eye (metacercariae) and Genarchella genarchella in the stomach; and the cestodes Proteocephalus macrophallus, Proteocephalus microscopicus, and Sciadocephalus megalodiscus in the intestines. Hysterothylacium sp. larvae (P = 86%) and P. microscopicus (P = 74%) were the most prevalent parasites. Anisakids were more prevalent and abundant in the dry season. A negative correlation between the abundances of Hysterothylacium sp. and P. microscopicus was observed, suggesting a competitive/antagonistic relationship between these parasites. Cichla piquiti represents a new host for four parasite species. These new records significantly increase the list of parasites of C. piquiti, contributing to the knowledge of the host-parasite relationship and the geographical distribution of these helminths.

Hepatozoon spp. are commonly found infecting snakes. Since the latter are parasitized by diverse forms and data in the literature show divergence, we studied Hepatozoon spp. diversity on Crotalus durissus terrificus snakes using both molecular and morphological approaches. Naturally infected animals were employed. Blood was collected, blood smears were prepared and an aliquot was stored at -20°C for DNA extraction. Five specimens of C. durissus terrificus were selected, each of them infected with one gamont type. Morphological and morphometric analyses of the found gamonts led to their grouping into three populations. For molecular characterization, seven oligonucleotide pairs that amplify distinct regions of rDNA gene were tested by adopting the PCR technique. Only the oligonucleotide pairs HepF300/Hep900 and HEMO1/HEMO2 were efficient in amplifying and distinguishing different isolates of Hepatozoon spp. from snakes. The better results were obtained when both oligonucleotide pairs were used in association. Based on the molecular and morphologic differences, three new species were proposed: Hepatozoon cuestensis sp. nov.; Hepatozoon cevapii sp. nov. and Hepatozoon massardii sp. nov. This is the first description of new Hepatozoon species from snakes, based on molecular characterization and morphological data, in South America., (Copyright © 2013 Elsevier Inc. All rights reserved.)

A total of 57 sairus (Cyphocharax nagelii) from the Peixe River, state of São Paulo, southeastern Brazil, were examined between April 2011 and February 2012. Eleven species of metazoan parasites were collected and identified: Palombitrema triangulum, Curvianchoratus hexacleidus, Curvianchoratus singularis, Sphincterodiplostomum musculosum, Contracaecum sp., Cacatuocotyle paranaensis, Cosmoxynemoides aguirrei, Amplexibranchius bryconis, Brasergasilus sp., Ergasilus sp. and Clinostomum sp. The monogenean P. triangulum was the most prevalent species (61.40%) with the highest mean intensity (4.88). The monogeneans C. hexacleidus and C. singularis, the digenean S. musculosum and the nematode Contracaecum sp. also showed high prevalence. Only S. musculosum presented significant correlation between the total body weight of the host and its abundance. The parasitic infracommunities had a mean Brillouin diversity (HB) of 1.165 ± 0.987 and the maximum diversity was 1.671. The sex and length of the hosts did not influence the abundance of any parasite species. The community of metazoans in C. nagelii from the Peixe River was characterized by high richness and low uniformity.

With the aim of creating an inventory of the metazoan gill parasites of Salminus hilarii in the Taquari River, state of São Paulo, Brazil, five species of monogeneans (Anacanthorus contortus, A. bicuspidatus, Annulotrematoides parisellei, Jainus iocensis and Tereancistrum arcuatus) are reported the first time for this host. A total of 28 fish were sampled quarterly between April 2011 and January 2012, with 10 hosts in a lentic ecosystem and 18 in a lotic ecosystem. Quantitative ecological descriptors (prevalence, intensity of infestation and abundance) were calculated for the purpose to comparing the two ecosystems sampled (lentic and lotic ecosystems). However, no quantitative difference between the lentic and lotic ecosystems was observed. The present study has made available a checklist for species of the genus Anacanthorus and their hosts and geographical distribution in the Neotropical region up to the present time.