Trypanosomatid diversity in a bat community of an urban area in Campo Grande, Mato Grosso do Sul, Brazil.

Bats have a long evolutionary history with trypanosomatids, but the role of these flying mammals on parasite transmission cycles in urban areas, especially for Trypanosoma and Leishmania species, remains poorly known. The objective of this study was to evaluate the species richness of trypanosomatids parasitizing a bat community in Campo Grande (CG), a state capital within the Cerrado of the Brazilian Midwest. We evaluated 237 bats of 13 species by means of hemoculture and molecular detection in spleen samples. The bat community of CG appears to participate in the transmission cycles of various species of trypanosomatids. We report an overall trypanosomatid detection rate of 34.2% (n = 81), involving 11 out of 13 sampled bat species. We identified six species of trypanosomatids from 61 bats by analyzing SSU rRNA and/or kDNA: Trypanosoma cruzi DTU TcI, T. c. marinkellei, T. dionisii, Leishmania infantum, L. amazonensis, and T. janseni, with this latter being detected by hemoculture for the first time in a bat species. We also detected a Molecular Operational Taxonomic Unit, Trypanosoma sp. DID, in the phyllostomids Glossophaga soricina and Platyrrhinus lineatus. The highest trypanosomatid richness was observed for Sturnira lilium, which hosted three species: L. infantum, T. dionisii and T. janseni. Given that visceral leishmaniasis is endemic in CG, special focus should be placed on L. infantum. Moreover, L. amazonensis and T. cruzi warrant attention, since these are zoonotic parasites responsible for human cases of tegumentary leishmaniasis and Chagas disease, respectively. In this respect, we discuss how bat communities may influence the Leishmania spp. transmission in endemic areas.

New insights into a poorly known parasite, Dero lutzi (Oligochaeta: Naididae), associated with tree frogs of the genus Scinax: morphological evaluation and genotypic data.

The oligochaete Dero lutzi follows a life strategy that alternates between free-living periods in aquatic environments and endoparasitic phases. Most occurrences of D. lutzi in anurans are reported in species with arboreal habits, with studies limited to the recording of the oligochaete's presence in the host. Our study recovered specimens of D. lutzi from the tree frogs Scinax fuscovarius and Scinax. nasicus. We performed a morphological assessment of the parasite using light microscopy, for the first time, scanning electron microscopy. Molecular characterization of D. lutzi was carried out using the mitochondrial gene 16S rRNA and the nuclear gene 28S rRNA. Additionally, a phylogenetic tree was constructed to assess the species´position in relation to other group members. In our results, we confirmed the phenotypic morphological characteristics of the endoparasitic phase of D. lutzi. We also presented its phylogenetic position with other oligochaetes in the group, demonstrating the proximity between the endoparasite D. lutzi and the free-living oligochaete D. superterrenus.

Raillietia auris (Mesostigmata: Raillietiidae) in cattle in the state of Mato Grosso do Sul, Brazil.

Parasitic otitis in cattle, caused by mites, has been reported from several continents. The present study aimed to determine the distribution, prevalence, intensity, mean intensity, and range of the agent in cattle in the state of Mato Grosso do Sul, Brazil. The samples were designed at random, with an acceptable margin of error of 3% and a confidence interval of 99%. A total of 449 animals were sampled immediately after slaughter from 34 different municipalities in the state using the technique of flushing both ear canals. Only Raillietia auris (Leidy, 1872) were found, with a prevalence of 98.6%, mean intensity of 53.78 mites/animal, and a range of 1-323. Impressively, the prevalence found was identical to another survey carried out 39 years ago in the same region. Details about the parasite intensity in different age categories of the animals are presented. The study demonstrates that the prevalence and intensity of infestation by Raillietia auris are high, and in older cattle are higher than young ones.

Dracunculiasis in a domestic dog in Brazil.

We report and discuss the surprising encounter of a dog naturally infected by Dracunculus sp. in Brazil, a brief clinical history of the animal and a procedure for removing the nematode. We also present details on the morphology of the fragments collected from the nematode and a phylogenetic comparison of the partial sequences of the mitochondrial 18S rRNA and cytochrome c oxidase subunit I (COI) genes, deposited with others in GenBank. The samples were an independent lineage forming a well-supported monophyletic assemblage with D. medinensis. We thus conclude that this species has not yet been sequenced or even described and will only be elucidated by more information because only two species of Dracunculus have been reported in Brazil, D. fuelleborni and D. brasiliensis.

Occurrence of larvae of trypanorhynch cestodes in snappers (Lutjanidae) from northeast Brazil / Ocorrência de larvas de cestodas trypanorhyncha em vermelhas (Lutjanidae) do nordeste do Brasil

Abstract Three species of snappers from artisanal, small-scale fisheries were examined for the presence of parasites. A total of 139 lutjanid fish were collected: 69 specimens of Lutjanus analis, 47 specimens of Lutjanus vivanus, and 23 specimens of Lutjanus synagris. Encysted plerocercoid of trypanorhynch cestodes found at necropsy in the viscera of snappers were sampled for parasitological analysis. These plerocercoid larvae belong to the genera Floriceps, Pseudogrillotia , and Oncomegas. Although these parasites do not have any zoonotic potential, fish with heavy loads of plerocercoids are rejected during inspection as they compromise meat hygiene. Our findings suggest that light larval cestode infections in lutjanids would not lead to consumer rejection of the food product. The occurrence of Floriceps sp. in L. analis and in L. synagris, of Pseudogrillotia sp. in L. vivanus and in L. synagris , and of Oncomegas sp. in L. synagris are new findings in these fish species. These parasites are new to these fish species and have not been reported in snappers from the northeast coast of Brazil. The results contribute to the existing body of knowledge about the parasitic fauna of fish and its distribution along the coastline of Brazil.

Resumo Três espécies de pargos de pescaria artesanal e de pequena escala foram examinadas quanto à presença de parasitas. Um total de 139 peixes lutjanídeos foram coletados: 69 espécimes de Lutjanus analis, 47 de Lutjanus vivanus e 23 de Lutjanus synagris. Cistos de plerocercóides de cestodas Trypanorhyncha encontrados durante a necrópsia nas vísceras de pargos foram amostrados para análise parasitológica. Estas larvas plerocercóides pertencem aos gêneros Floriceps, Pseudogrillotia e Oncomegas. Embora esses parasitas não tenham qualquer potencial zoonótico, peixes com elevadas cargas de plerocercóides são rejeitados durante a inspeção, pois comprometem a higiene da carne. Os achados sugerem que baixas infecções por essas formais larvais de cestodas em lutjanídeos não levariam a rejeição do consumidor quanto ao produto alimentar. A ocorrência de Floriceps sp. em L. analis e em L. synagris, de Pseudogrillotia sp. em L. vivanus e em L. syngaris, e de Oncomegas sp. em L. synagris são novas descobertas nestas espécies de peixes. Estes parasitas são novos para essas espécies de peixes e não foram relatados em pargos da costa nordeste do Brasil. Os resultados contribuem para o conhecimento existente sobre a fauna parasitária do peixe e sua distribuição ao longo do litoral do Brasil.

Integrative approach on Pharyngodonidae (Nematoda: Oxyuroidea) parasitic in reptiles: Relationship among its genera, importance of their diagnostic features, and new data on Parapharyngodon bainae.

The first integrative approach using sequences of two genes (18S and 28S rRNA) plus morphological and life history traits, was explored in Pharyngodonidae nematodes parasitic in reptiles. Additionally, first genetic characterization of Parapharyngodon bainae and new data on its morphology are given. This approach evaluated the phylogenetic relationships among genera within Pharyngodonidae, as well as the importance of their diagnostic morphological features. Specimens of P. bainae were collected from faecal pellets of the lizard Tropidurus torquatus in the State of Minas Gerais, Brazil. Nematodes were fixed for scanning electron microscopy and molecular procedures. Morphological observations revealed the accurate structures of cephalic end, of cloacal region in males, of vulva and eggs. Phylogenetic reconstructions were based upon four datasets: aligned sequences of the 18S, of the 28S, of both concatenated genes and of combined morphological and molecular datasets. Bayesian inference and maximum likelihood were performed to infer the phylogenies of molecular datasets and maximum parsimony to infer that of all-combined data. Pharyngodonid parasites of reptiles seem to configure two general monophyletic lineages, as previously assertions. Results also showed the monophyly of Spauligodon, Skrjabinodon and Parapharyngodon, as well as the clear separation between the latter and Thelandros. Combination of datasets improved nodal supports. Analysis of the all-combined datasets revealed the importance of vulval position and egg morphology as phylogenetic informative traits. However, characters of male caudal morphology appear as are highly homoplastic, and seem to be product of convergent evolution or multiple losses of ancestral traits. The closely-related Thelandros and Parapharyngodon are kept valid and their diagnosis should be based upon the position of the operculum in eggs (terminal or subterminal, respectively). Some inconsistencies in the scarce molecular and morphological databases were noted. Thus, new genetic data is required for further conclusions and current database must be evaluated with attention.

Occurrence of larvae of trypanorhynch cestodes in snappers (Lutjanidae) from northeast Brazil.

Three species of snappers from artisanal, small-scale fisheries were examined for the presence of parasites. A total of 139 lutjanid fish were collected: 69 specimens of Lutjanus analis, 47 specimens of Lutjanus vivanus, and 23 specimens of Lutjanus synagris. Encysted plerocercoid of trypanorhynch cestodes found at necropsy in the viscera of snappers were sampled for parasitological analysis. These plerocercoid larvae belong to the genera Floriceps, Pseudogrillotia , and Oncomegas. Although these parasites do not have any zoonotic potential, fish with heavy loads of plerocercoids are rejected during inspection as they compromise meat hygiene. Our findings suggest that light larval cestode infections in lutjanids would not lead to consumer rejection of the food product. The occurrence of Floriceps sp. in L. analis and in L. synagris, of Pseudogrillotia sp. in L. vivanus and in L. synagris , and of Oncomegas sp. in L. synagris are new findings in these fish species. These parasites are new to these fish species and have not been reported in snappers from the northeast coast of Brazil. The results contribute to the existing body of knowledge about the parasitic fauna of fish and its distribution along the coastline of Brazil.

Morphological and morphometric features of nematode-cysts in Gymnotus inaequilabiatus liver in the Brazilian Pantanal.

The aim of this study was to determine the morphometric measures and morphological aspects of nematode-cysts in Gymnotus inaequilabiatus, and the presence of melanomacrophage centers (MMCs) associated with the periphery of cysts and in the liver parenchyma. Adult specimens, 34 female (123.1 ± 43.9g) and 45 male (135.5 ± 43.4g), from Paraguay River, Corumbá, Brazil, were used. The number of nematode-cysts was determined in 79 livers and 25 of them randomly selected for histopathological analysis and morphometric measures of nematode-cysts (mean diameter, thickness of collagen layer, and cyst-wall layer). The percentage of cysts with MMCs on the periphery and density in the liver parenchyma was estimated. The average number of macroscopic cysts was of 48.7 ± 2.78. Granulomatous reaction was observed surrounding the cysts. Diameter, collagen layer and cyst-wall measurements were 293.0 ± 75.18 (µm), 17.72 ± 6.01 (µm) and 12.21 ± 9.51 (µm), respectively. The number of nematode-cysts was correlated with hepatosomatic index, (r=0.26, P<0.05). Collagen layer was correlated with cyst diameter (r=0.62, P<0.01). Pericystic and parenchymatous MMCs were moderately (r=0.48) and highly (r=0.90) correlated with nematode-cysts number. Morphological characteristics of hepatic tissue and cysts-nematodes measures suggest that G. inaequilabiatus acts as a paratenic host to nematodes in the larval stage.

Morphological and morphometric features of nematode-cysts in Gymnotus inaequilabiatus liver in the Brazilian Pantanal / Características morfológicas e morfométricas de cistos de nematódeos em fígado de Gymnotus inaequilabiatus no Pantanal brasileiro

Abstract The aim of this study was to determine the morphometric measures and morphological aspects of nematode-cysts in Gymnotus inaequilabiatus, and the presence of melanomacrophage centers (MMCs) associated with the periphery of cysts and in the liver parenchyma. Adult specimens, 34 female (123.1 ± 43.9g) and 45 male (135.5 ± 43.4g), from Paraguay River, Corumbá, Brazil, were used. The number of nematode-cysts was determined in 79 livers and 25 of them randomly selected for histopathological analysis and morphometric measures of nematode-cysts (mean diameter, thickness of collagen layer, and cyst-wall layer). The percentage of cysts with MMCs on the periphery and density in the liver parenchyma was estimated. The average number of macroscopic cysts was of 48.7 ± 2.78. Granulomatous reaction was observed surrounding the cysts. Diameter, collagen layer and cyst-wall measurements were 293.0 ± 75.18 (µm), 17.72 ± 6.01 (µm) and 12.21 ± 9.51 (µm), respectively. The number of nematode-cysts was correlated with hepatosomatic index, (r=0.26, P<0.05). Collagen layer was correlated with cyst diameter (r=0.62, P<0.01). Pericystic and parenchymatous MMCs were moderately (r=0.48) and highly (r=0.90) correlated with nematode-cysts number. Morphological characteristics of hepatic tissue and cysts-nematodes measures suggest that G. inaequilabiatus acts as a paratenic host to nematodes in the larval stage.

Resumo O objetivo deste estudo foi determinar as características morfológicas e morfométricas de cistos de nematodas em fígado de Gymnotus inaequilabiatus, e a presença de centros de melanomacrófagos (CMMs) pericísticos e no parênquima hepático. Espécimes adultos, 34 fêmeas (123,1 ± 43,9 g) e 45 machos (135,5 ± 43,4g), provenientes do Rio Paraguai, Corumbá, Brasil foram utilizados. Os cistos foram quantificados em 79 fígados. Em 25 fígados foi realizada a análise histopatológica e morfometria dos cistos (diâmetro, espessura da camada de colágeno e da parede). Estimou-se a porcentagem de cistos com CMMs periférico e a densidade de CMMs no parênquima. A média de cistos macroscópicos foi de 48,7 ± 2,78. Observou-se reação granulomatosa pericística. O diâmetro, a espessura da camada de colágeno e da parede do cisto foi de 293,0 ± 75,18 (µm), 17,72 ± 6,01 (µm) e 12,21 ± 9,51 (µm), respectivamente. O número de cistos foi associado ao índice hepatossomático, (r=0,26, P <0,05). A camada de colágeno correlacionou-se com o diâmetro do cisto (r=0,62, P <0,01). CMMs pericísticos e do parênquima apresentaram correlação moderada (r=0,48) e alta (r=0,90) com o número de cistos, respectivamente. As características morfológicas do tecido hepático e a morfometria dos cistos de nematodas sugerem que G. inaequilabiatus atua como hospedeiro paratênico para larvas de nematodas.

Efficacy of treatments with toltrazuril 7.5% and lasalocid sodium in sheep naturally infected with Eimeria spp.

The objective of this study was to evaluate the efficacy of an experimental formulation of toltrazuril 7.5% + Trimix™ on a naturally acquired infection of Eimeria spp. in suckling lambs kept on pasture and, in another trial, evaluate the comparative efficacy between lasalocid and toltrazuril 7.5% + Trimix™ in newly weaned sheep under feedlot conditions that had been naturally infected with Eimeria spp. In the first experiment, 30 suckling lambs were divided into two groups: A - treated with toltrazuril 7.5% + Trimix™ and B- control. In experiment 2, 30 weaned sheep were divided into three groups: I - treated with toltrazuril 7.5% + Trimix™, II - treated with lasalocid and III - control. Treatment group A showed an efficacy of 90, 99.4 and 87.3% on days 5, 10 and 20, respectively. Treatment group I had an efficacy of 98.2, 92.6 and 94.5%, while group II had an efficacy of 72.7, 81.6 and 95.9% on days 7, 21 and 42, respectively. Eight Eimeria species were identified; E. ovinoidalis was the most common. Treatment with the toltrazuril 7.5% +Trimix ™ formulation was effective against Eimeria spp. in suckling lambs in field conditions and lambs weaned in under feedlot conditions.

Efficacy of treatments with toltrazuril 7. 5% and lasalocid sodium in sheep naturally infected with Eimeria spp / Eficácia de tratamentos com toltrazuril 7, 5% e lasalocida sódica em ovinos naturalmente infectados com Eimeria spp

Abstract The objective of this study was to evaluate the efficacy of an experimental formulation of toltrazuril 7.5% + Trimix™ on a naturally acquired infection of Eimeria spp. in suckling lambs kept on pasture and, in another trial, evaluate the comparative efficacy between lasalocid and toltrazuril 7.5% + Trimix™ in newly weaned sheep under feedlot conditions that had been naturally infected with Eimeria spp. In the first experiment, 30 suckling lambs were divided into two groups: A - treated with toltrazuril 7.5% + Trimix™ and B- control. In experiment 2, 30 weaned sheep were divided into three groups: I - treated with toltrazuril 7.5% + Trimix™, II - treated with lasalocid and III - control. Treatment group A showed an efficacy of 90, 99.4 and 87.3% on days 5, 10 and 20, respectively. Treatment group I had an efficacy of 98.2, 92.6 and 94.5%, while group II had an efficacy of 72.7, 81.6 and 95.9% on days 7, 21 and 42, respectively. Eight Eimeria species were identified; E. ovinoidalis was the most common. Treatment with the toltrazuril 7.5% +Trimix ™ formulation was effective against Eimeria spp. in suckling lambs in field conditions and lambs weaned in under feedlot conditions.

Resumo O objetivo deste estudo foi avaliar a eficácia de uma formulação experimental de toltrazuril 7,5% + Trimix™ em cordeiros mantidos em pastagem com infecção naturalmente adquirida por Eimeria spp. e, em outro teste, a eficácia comparativa entre lasalocida sódica e toltrazuril 7,5% + Trimix™ em ovinos recém-desmamados, naturalmente infectados com Eimeria spp. em condições de confinamento. No primeiro experimento, 30 cordeiros lactantes foram divididos em dois grupos: A - tratados com toltrazuril 7,5% + Trimix™; e B - controle. No experimento 2, 30 ovinos desmamados foram divididos em três grupos: I - tratados com toltrazuril 7,5% + Trimix™; II - tratados com lasalocida sódica; e III - controle. O grupo A (tratado) obteve uma eficácia de 90, 99,4 e 87,3% nos dias 5, 10 e 20, respectivamente. O grupo I teve eficácia de 98,2, 92,6 e 94,5%, enquanto o grupo II teve uma eficácia de 72,7, 81,6 e 95.9% nos dias 7, 21 e 42, respectivamente. Foram identificadas oito espécies de Eimeria sendo E. ovinoidalis a mais comum. O tratamento com a formulação de toltrazuril 7,5% + Trimix™ foi eficaz contra Eimeria spp. em cordeiros em lactação em condições de campo e em ovinos desmamados em confinamento.

Estimates of coextinction risk: how anuran parasites respond to the extinction of their hosts.

Amphibians are known as the most threatened vertebrate group. One of the outcomes of a species' extinction is the coextinction of its dependents. Here, we estimate the extinction risk of helminth parasites of South America anurans. Parasite coextinction probabilities were modeled, assuming parasite specificity and host vulnerability to extinction as determinants. Parasite species associated with few hosts were the most prone to extinction, and extinction risk varied amongst helminth species of different taxonomic groups and life cycle complexity. Considering host vulnerability in the model decreased the extinction probability of most parasites species. However, parasite specificity and host vulnerability combined to increase the extinction probabilities of 44% of the helminth species reported in a single anuran species.

How Many Parasites Species a Frog Might Have? Determinants of Parasite Diversity in South American Anurans.

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.

Fishes from Baía da Medalha, southern Pantanal, Brazil: A 20 years review / Peixes da Baía da Medalha, Pantanal Sul, Brasil: Uma revisão de 20 anos

Abstract Located in the Pantanal of Miranda-Abobral, the Baía da Medalha is the largest pond close to the Base de Estudos do Pantanal of the Universidade Federal de Mato Grosso do Sul. The Baía da Medalha has been a study site for several didactic and scientific projects for years. Nevertheless, its fish fauna has never been inventoried. Based on data collected from the beginning of the 1990s up to 2011, we provide a list of fish species from the Baía da Medalha. A total of 97 species were recorded, corresponding to about 40% of the species stated for the Pantanal. Characiformes and Siluriformes were the most species-rich orders, being Characidae and Cichlidae the families with the highest number of species. Regional seasonal flood dynamics and the abundance of aquatic macrophytes may be associated with this high diversity. The representative richness found in this lagoon highlights the importance of such taxonomic surveys to preserve the diversity of aquatic habitats within the Pantanal ecosystem.

Resumo Localizada no Pantanal do Miranda-Abobral, a Baía da Medalha é a maior e mais próxima lagoa da Base de Estudos do Pantanal da Universidade Federal de Mato Grosso do Sul. A Baía da Medalha tem sido área de estudo de diversos projetos didáticos e científicos há anos, entretanto, nenhum inventário sobre sua ictiofauna foi realizado. Aqui é apresentada uma lista de espécies de peixes da Baía da Medalha baseado em dados de coletas do começo da década de 90 até 2011. Um total de 97 espécies foi registrado, correspondendo è cerca de 40% do total de espécies registradas para o Pantanal. Characiformes e Siluriformes foram as ordens mais ricas em espécies, sendo Characidae e Cichlidae as famílias com maior número de espécies. Dinâmicas de inundação sazonal e a abundância de macrófitas aquáticas podem ser associadas a esta alta diversidade. A representativa riqueza encontrada nesta lagoa ressalta a importância de levantamentos taxonômicos a fim de preservar a diversidade dos habitats aquáticos do dentro do ecossistema do Pantanal.

Checklist of Helminth parasites of Amphibians from South America.

Parasitological studies on helminths of amphibians in South America have increased in the past few years. Here, we present a list with summarized data published on helminths of South American amphibians from 1925 to 2012, including a list of helminth parasites, host species, and geographic records. We found 194 reports of helminths parasitizing 185 amphibian species from eleven countries: Argentina, Brazil, Chile, Colombia, Equador, French Guyana, Guyana, Paraguay, Peru, Uruguay and Venezuela. Helminth biodiversity includes 278 parasite species of the groups Acanthocephala, Nematoda, Cestoda, Monogenea and Trematoda. A list of helminth parasite species per host, and references are also presented. This contribution aims to document the biodiversity of helminth parasites in South American amphibians, as well as identify gaps in our knowledge, which in turn may guide subsequent studies. 

Metazoan endoparasites of Pygocentrus nattereri (Characiformes: Serrasalminae) in the Negro River, Pantanal, Brazil.

In the period of October 2007 to August 2008, 152 specimens of Pygocentrus nattereri were caught in the Negro River in the Nhecolândia region, central Pantanal wetland, State of Mato Grosso do Sul, Brazil. The specimens were necropsied and a total of 4,212 metazoan endoparasites were recovered, belonging to 10 taxons: Procamallanus (Spirocamallanus) inopinatus, Philometridae gen. sp., Eustrongylides sp., Brevimulticaecum sp., Contracaecum sp. (Nematoda), Echinorhynchus paranensis (Acanthocephala), Leiperia gracile, Sebekia oxycephala, Subtriquetra sp. 1 and Subtriquetra sp. 2 (Pentastomida). This is the first record of two parasite species from P. nattereri: E. paranensis and L. gracile.

Metazoan endoparasites of Pygocentrus nattereri (Characiformes: Serrasalminae) in the Negro River, Pantanal, Brazil / Endoparasitas metazoários de Pygocentrus nattereri (Caraciformes: Serrasalminae) no rio Negro, Pantanal, Brasil

In the period of October 2007 to August 2008, 152 specimens of Pygocentrus nattereri were caught in the Negro River in the Nhecolândia region, central Pantanal wetland, State of Mato Grosso do Sul, Brazil. The specimens were necropsied and a total of 4,212 metazoan endoparasites were recovered, belonging to 10 taxons: Procamallanus (Spirocamallanus) inopinatus, Philometridae gen. sp., Eustrongylides sp., Brevimulticaecum sp., Contracaecum sp. (Nematoda), Echinorhynchus paranensis (Acanthocephala), Leiperia gracile, Sebekia oxycephala, Subtriquetra sp. 1 and Subtriquetra sp. 2 (Pentastomida). This is the first record of two parasite species from P. nattereri: E. paranensis and L. gracile.

No período de outubro de 2007 a agosto de 2008, 152 espécimes de Pygocentrus nattereri foram capturados no rio Negro na região da Nhecolândia, parte central do Pantanal, Mato Grosso do Sul, Brasil. Os espécimes foram necropsiados e um total de 4.212 endoparasitas metazoários foram colhidos, pertencentes a 10 táxons: Procamallanus (Spirocamallanus) inopinatus, Philometridae gen. sp., Eustrongylides sp., Brevimulticaecum sp., Contracaecum sp. (Nematoda), Echinorhynchus paranensis (Acanthocephala), Leiperia gracile, Sebekia oxycephala, Subtriquetra sp. 1 e Subtriquetra sp. 2 (Pentastomida). Este é o primeiro registro de duas espécies de parasitas em P. nattereri: E. paranensis e L. gracile.

Brazilian catfish parasitized by Epistylis sp. (Ciliophora, Epistylididae), with description of parasite intensity score.

The determination of mean intensity of parasitism for colony-forming sessile protozoan such as Epistylis has been a great problem in parasitological studies. Some alternatives have been proposed by researchers for laboratory and field conditions. This study describes the criteria to establish the parasitic intensity score for epistylidid infestation in fish. Parasite distribution and the host-parasite relationship in four species of Brazilian cultured catfish and their hybrids are discussed. The highest prevalence rates were found in the hybrid jundiara, Leiarius marmoratus male × Pseudoplatystoma reticulatum female (96.4 %), followed by jurupoca, Hemisorubim platyrhynchos (60 %), and the hybrid surubim, Pseudoplatystoma corruscans male × P. reticulatum female (52.7 %). Positive correlation between parasitic intensity score and the fish size, weight, and relative condition factor were also observed. These findings indicate that Epistylis infestation in Brazilian catfish is an emerging disease in cultured fish.

Tissue alterations in the pirarucu, Arapaima gigas, infected by Goezia spinulosa (Nematoda).

Five specimens of Arapaima gigas caught in the Araguaia River (State of Mato Grosso, Brazil) were investigated for helminths in 2004. Numerous adult specimens of the rhapidascarid nematode Goezia spinulosa were found in stomach ulcers in all the specimens of A. gigas and were surrounded by thickening of the mucosa. The gastric glands of all the fish were necrotic and there was a severe and diffuse inflammatory reaction composed of eosinophils (which were predominant), lymphocytes and rare macrophages in the mucosa, submucosa and muscle layer. This is the first report of tissue lesion occurrences in this host, in the presence of G. spinulosa, and it confirms the high pathogenicity of this parasite species.

Tissue alterations in the pirarucu, Arapaima gigas, infected by Goezia spinulosa (Nematoda) / Alterações teciduais em pirarucu, Arapaima gigas, infectado por Goezia spinulosa (Nematoda)

Five specimens of Arapaima gigas caught in the Araguaia River (State of Mato Grosso, Brazil) were investigated for helminths in 2004. Numerous adult specimens of the rhapidascarid nematode Goezia spinulosa were found in stomach ulcers in all the specimens of A. gigas and were surrounded by thickening of the mucosa. The gastric glands of all the fish were necrotic and there was a severe and diffuse inflammatory reaction composed of eosinophils (which were predominant), lymphocytes and rare macrophages in the mucosa, submucosa and muscle layer. This is the first report of tissue lesion occurrences in this host, in the presence of G. spinulosa, and it confirms the high pathogenicity of this parasite species.

Cinco espécimens de Arapaima gigas capturados no Rio Araguaia (Estado do Mato Grosso, Brasil) foram investigados para diagnóstico de infecção por helmintos em 2004. Numerosos espécimes adultos do nematóide rafidascarídeo Goezia spinulosa foram encontrados em úlceras do estômago circundadas por um espessamento da mucosa em todos os exemplares de A. gigas. As glândulas gástricas de todos encontravam-se necróticas e havia um acentuado e difuso infiltrado inflamatório composto por eosinófilos, que eram predominantes, linfócitos e raros macrófagos na mucosa, submucosa e camada muscular. As lesões teciduais na presença de nematóide G. spinulosa são relatadas pela primeira vez nesse hospedeiro e confirmam a alta patogenicidade dessa espécie de parasito.