Resumo O objetivo deste estudo foi determinar a atividade alergênica de componentes presentes em extratos crus de plerocercos (CPE) e de blastocistos de Pterobothrium crassicolle (CBE), obtidos de Micropogonias furnieri, em modelo murino. Dois grupos de sete animais receberam cada um 50 µg de CPE ou CBE nos dias 1, 35 e 120. As amostras de soro foram testadas por ELISA e Imunoblot. Os níveis específicos de IgG e IgE foram detectados por ELISA, mostrando respostas humorais específicas para a imunização primária para ambas as imunoglobulinas e títulos crescentes de IgE. Testes positivos de Anafilaxia Cutânea Passiva em ratos sensibilizados com soros anti-CBE e testados por CBE, demonstraram biologicamente, a atividade alergênica dos extratos. O CPE e o CBE evidenciaram algumas regiões de reconhecimento diferentes, mas ambos os grupos experimentais reconheceram todas as regiões dos extratos, quando testados para reações cruzadas, mostrando que o CPE e o CBE poderiam compartilhar locais de reconhecimento antigênico. (CPE , (CBE) furnieri murino 5 1 3 120 Imunoblot antiCBE anti biologicamente diferentes cruzadas antigênico (CBE 12

Abstract The aim of this study was to determine the allergenic activity of components present in crude extracts of Pterobothrium crassicolle plerocerci (CPE) and blastocysts (CBE) obtained from Micropogonias furnieri in a murine model. Two groups of seven animals each received 50 µg of CPE or CBE on days 1, 35 and 120. Serum samples were tested by ELISA and Immunoblotting. Specific IgG and IgE levels were detected by ELISA, showing specific humoral responses for the primary immunization for both immunoglobulins and continuously growing titers for IgE. Positive Passive Cutaneous Anaphylaxis tests in rats sensitized with anti-CBE sera and tested by CBE, showed biologically, the allergenic activity of the extracts. The CPE and CBE showed some different recognition regions but both experimental groups recognized all regions of the extracts when tested for cross reactions, showing that CPE and CBE could share antigenic recognition sites. (CPE (CBE model 5 1 3 120 Immunoblotting antiCBE anti biologically reactions sites 12

Resumo Alguns parasitos de peixes podem causar uma variedade de sintomas em humanos, incluindo alergias. Este foi um estudo transversal baseado em entrevistas, análise sérica por ELISA para IgG anti–Pterobothrium heteracanthum e avaliação estatística. Quatro indivíduos foram sororreativos (6,25%), sem associação com o manuseio dos peixes (p = 1,000) ou com a ingestão maior que duas vezes por semana (p = 0,232). Houve associação significativa (p=0,032) entre reatividade e ausência de sintomas alérgicos. A sororreatividade contra P. heteracanthum em humanos foi detectada, mas não foi associada à quantidade de peixe ingerido, manuseado ou a queixas alérgicas. alergias entrevistas antiPterobothrium anti Pterobothrium estatística 6,25%, 625 6,25% , 6 25 (6,25%) p 1,000 1000 1 000 0,232. 0232 0,232 . 0 232 0,232) p=0,032 p0032 032 (p=0,032 alérgicos P detectada ingerido alérgicas 62 6,25 2 (6,25% 1,00 100 00 023 0,23 23 p=0,03 p003 03 (p=0,03 6,2 (6,25 1,0 10 02 0,2 p=0,0 p00 (p=0,0 6, (6,2 1, 0, p=0, p0 (p=0, (6, p=0 (p=0 (6 p= (p= (

Abstract Some fish parasites can cause a variety of symptoms in humans, including allergies. This was a cross-sectional study based on interviews, serum analysis by ELISA for anti–Pterobothrium heteracanthum IgG and a statistical evaluation. Four individuals were seroreactive (6.25%), with no association with fish handling (p = 1.000) or with ingestion more than twice a week (p = 0.232). There was a significant association (p = 0.032) between reactivity and the absence of allergy symptoms. Seroreactivity against P. heteracanthum in humans was detected, but was not associated with the amount of fish ingested, handled, or with allergic complaints. allergies crosssectional cross sectional interviews antiPterobothrium anti Pterobothrium evaluation 6.25%, 625 6.25% , 6 25 (6.25%) p 1.000 1000 1 000 0.232. 0232 0.232 . 0 232 0.232) 0.032 0032 032 P detected ingested handled complaints 62 6.25 2 (6.25% 1.00 100 00 023 0.23 23 0.03 003 03 6.2 (6.25 1.0 10 02 0.2 0.0 6. (6.2 1. 0. (6. (6 (

Abstract Hyporthodus niveatus is an appreciated and valuable commercial fish species in the municipality of Niterói, state of Rio de Janeiro, Brazil, due its excellent quality flesh. The constant presence of helminths in the abdominal musculature, viscera and serosa of individuals of the species has been the subject of complaints among local fish traders because of economic losses due to their repugnant aspect. Considering their hygienic-sanitary importance and significance for collective health, the presence of helminths was investigated in 20 individual fish of H. niveatus purchased from fish markets in the municipality of Niterói in 2021-2022. Nematodes, identified as third-instar larvae of Contracaecum sp., Terranova sp., Hysterothylacium deardorffoverstreetorum and Raphidascaris sp., were found parasitizing the intestine and abdominal cavity. Acanthocephalans, identified as juveniles of Corynosoma australe, were found parasitizing the intestine. The highest parasitic indices were for H. deardorffoverstreetorum, with prevalence of 30%, mean intensity of 1.5, mean abundance of 0.45 and infection ranges of 1-2. Considerations about the zoonotic potential and hygienic-sanitary significance of these parasites are presented in order to increase food safety for consumers. Janeiro Brazil flesh musculature aspect hygienicsanitary hygienic sanitary health 2 H 20212022. 20212022 2021 2022. 2022 2021-2022 Nematodes thirdinstar third instar sp sp. cavity Acanthocephalans australe 30 30% 15 1 5 1.5 045 0 45 0.4 12. 12 2. 1-2 consumers 2021202 202 2021-202 3 1. 04 4 0. 1- 202120 2021-20 20212 2021-2 2021-

Abstract Fistularia petimba is a fish species that has gained growing interest due to its appreciation for sushi and sahimi in Japanese restaurants of the coastal cities of Cabo Frio and Armação de Búzios, state of Rio de Janeiro, Brazil. The constant presence of helminths in the viscera, serosa and adjacent musculature of this fish has been the subject of important complaints among local fish traders, because of economic losses due to their repugnant aspect. Considering their hygienic-sanitary importance and significance for collective health, the presence of helminth larvae was investigated in 32 individual fish of F. petimba purchased from fish markets in the municipality of Cabo Frio in 2019. Cestode larvae, identified as Tentacularia coryphaenae, were found parasitizing the abdominal cavity and mesentery. Nematode larvae, identified as Hysterothylacium fortalezae and H. deardorffoverstreetorum, were found parasitizing stomach, intestine, liver, spleen, liver serosa, mesentery and abdominal cavity. Hysterothylacium fortalezae had the highest parasitic indices, with a prevalence of 43.75%, mean intensity of 8.07, mean abundance of 3.53 and range of infection of 3-25 specimens per host. Considerations of the zoonotic potential and hygienic-sanitary significance of these helminths are presented to increase food safety for consumers.

Abstract Balistes capriscus is an appreciated fish species in the state of Rio de Janeiro, Brazil, due its excellent quality flesh. The constant presence of helminth larvae in the abdominal musculature, viscera and serosa of individuals of the species has been the subject of complaints among local fish traders because of economic losses due to their repugnant aspect. Considering their hygienic-sanitary importance and significance for collective health, the presence of helminth larvae was investigated in 44 individual fish of B. capriscus purchased from fish markets in the municipalities of Rio de Janeiro, Niterói, Campos dos Goytacazes and Cabo Frio, state of Rio de Janeiro, in 2017–2018. Cestode larvae, identified as Diphyllobothriidae gen. sp. and Callitetrarhynchus gracilis, were found parasitizing the abdominal cavity, abdominal musculature, mesentery and liver serosa. Nematode (Raphidascaridiidae) third-instar larvae, identified as Hysterothylacium deardorffoverstreetorum and Raphidascaris sp., were found parasitizing stomach, intestine, liver, spleen, liver serosa, mesentery and abdominal cavity. The highest parasitic indices were for Raphidascaris sp., with prevalence of 70.45%, mean intensity of 15.61, mean abundance of 11 and infection range of 1–76 specimens per host. Considerations of the zoonotic potential and hygienic-sanitary significance of these helminths are presented to increase food safety for consumers.

Abstract Percophis brasiliensis is a fish species appreciated as a fried appetizer at beachside kiosks of Niterói, state of Rio de Janeiro, Brazil. The constant presence of helminth larvae in the viscera and serosa of individuals of the species has been the subject of complaints among local fish traders because of economic losses due to their repugnant aspect. Considering their hygienic-sanitary importance and significance for collective health, the presence of helminth larvae was investigated in 64 individual fish of P. brasiliensis purchased from Niterói fish markets in 2019. Cestodes, identified as larvae of Grillotia carvajalregorum, were found parasitizing the serosa of the stomach, mesentery and abdominal cavity. Nematodes, identified as third-instar larvae of Contracaecum sp., Terranova sp., Hysterothylacium deardorffoverstreetorum, H. fortalezae and Raphidascaris sp., were found parasitizing the stomach, intestine, liver, gonads, stomach serosa, mesentery and abdominal cavity. The highest parasitic indices were for G. carvajalregorum and H. deardorffoverstreetorum, with prevalences of 100% and 81.25%, mean intensities of 8.05 and 8.13, mean abundances of 8.05 and 6.61 and infection ranges of 1–131 and 1–42 specimens per host, respectively. Considerations about the zoonotic potential and hygienic-sanitary significance of these parasites are presented in order to increase food safety for consumers.

Resumo Consumir peixe constitui papel importante na dieta humana. Hoplias malabaricus, comumente chamado de traíra, peixe de água doce largamente apreciado no Brasil, é frequentemente infectado com larvas de quarto estágio (L4) de Eustrongylides sp. O presente estudo objetivou avaliar o potencial alergênico do Extrato Bruto de L4 de Eustrongylides sp. (EBE). Camundongos BALB/c foram imunizados intraperitonealmente (IP) por 10 μg de EBE com 2 mg de hidróxido de alumínio nos dias 0 e 35. Após imunização, determinaram-se níveis específicos de anticorpos IgG e IgE e avaliou-se a imunidade celular pela reação intradérmica no pavilhão auricular. Realizou-se sensibilização epicutânea na região dorsal pela exposição ao antígeno, utilizando-se câmara tipo Finn, contendo 50 μg de CEE ou solução salina. Após exposições, foram avaliados níveis específicos de anticorpos. Na imunização via IP, houve aumento gradual nos níveis de anticorpos IgG e produção de IgE transitória. Foi observado aumento significativo na espessura do pavilhão auricular na reação de hipersensibilidade celular. Na exposição ao antígeno pela via epicutânea, o EBE induziu aumento significante nos níveis de anticorpos IgG e IgE específicos e induziu imunidade celular. Pela primeira vez, observou-se que a imunização intraperitoneal e contato epicutâneo com antígenos larvares de Eustrongylides sp. são capazes de induzir sensibilização imunológica em camundongos.

Abstract Fish consumption plays an important role in human diet. Hoplias malabaricus, commonly known as traíra, is a freshwater fish widely appreciated in several Brazilian states and frequently infected by Eustrongylides sp. fourth-instar larvae (L4). The aim of the present study was to evaluate allergenic potential of Eustrongylides sp. L4 crude extract (CEE). BALB/c mice were immunized intraperitoneally (IP) by 10 μg CEE with 2 mg of aluminum hydroxide on days 0 and 35. Specific IgG and IgE antibody levels were determined after immunization and cellular immunity was evaluated by assessing intradermal reaction in ear pavilion. Epicutaneous sensitization was performed in dorsal region by antigen exposure using a Finn-type chamber containing 50 μg of CEE or saline solution, followed by evaluation of specific antibody levels. IP immunization resulted in a gradual increase in IgG antibody levels and transitory IgE production. Significant increase in ear thickness was observed in cellular hypersensitivity reaction. In case of antigen exposure by epicutaneous route, CEE was able to induce meaningfully increased levels of specific IgG and IgE antibodies as well as heightened cellular immunity. Both intraperitoneal immunization and epicutaneous contact with Eustrongylides sp. larval antigens were observed for first time to be capable of inducing immunological sensitization in mice.

Resumo Hoplias malabaricus (Characiformes, Erythrinidae), traíra, é um peixe neotropical de água doce que tem significante impacto na economia e saúde pública. De abril de 2016 a abril de 2018, foram adquiridos 45 espécimes de H. malabaricus comercializados no município de Magé, Estado do Rio de Janeiro, Brasil. Os peixes foram necropsiados e filetados para investigação da presença de larvas de nematoides. Vinte dos peixes coletados estavam parasitados por 347 larvas de nematoides, identificadas taxonomicamente como larvas de quarto estágio de Eustrongylides sp. usando-se dados morfológicos, morfométricos e moleculares, apresentando os seguintes valores: prevalência de 44,44%, intensidade média de 17,35, abundância média de 7,71, e amplitude de variação da infecção de 2-40. Os sítios de infecção foram musculatura, mesentério, cavidade abdominal e serosas do intestino, estômago e fígado. Este é o primeiro registro de larvas de Eustrongylides sp. parasitando H. malabaricus no Estado do Rio de Janeiro.

Abstract Hoplias malabaricus (Characiformes, Erythrinidae), trahira, is a neotropical freshwater fish of economic and public health significance. A total of 45 specimens of H. malabaricus commercialized in the municipality of Magé, state of Rio de Janeiro, Brazil, were acquired between April 2016 and April 2018 to investigate the presence of nematode larvae. Twenty of the fish were found parasitized by 347 fourth-stage nematode larvae identified taxonomically as Eustrongylides sp. using morphological, morphometric and molecular data. The parasitic indices were: prevalence 44.44%, mean intensity 17.35, mean abundance 7.71, and range of infection 2-40. Infection sites were musculature, mesentery, abdominal cavity, and serosa of intestine, stomach and liver. This is the first report of Eustrongylides sp. larvae parasitizing H. malabaricus in the state of Rio de Janeiro.

Resumo Os linguados são peixes comercial e economicamente importantes. Um total de 120 espécimes de linguados (60 Paralichthys isosceles, 30 P. patagonicus e 30 Xystreurys rasile) foram coletados no litoral do estado do Rio de Janeiro, Brasil. Os peixes foram medidos, necropsiados, filetados e tiveram seus órgãos investigados para a presença de acantocéfalos. A identificação taxonômica foi baseada em caracteres morfológicos, morfométricos e genéticos. Paralichthys isosceles e P. patagonicus estavam parasitados por acantocéfalos juvenis de Serrasentis sagittifer, Bolbosoma turbinella, Corynosoma australe e C. cetaceum; Xystreurys rasile estava parasitado com C. australe. A caracterização genética confirmou a identificação dos espécimes de Bolbosoma turbinella e Corynosoma australe, como demonstrado por análises filogenéticas usando ambos marcadores moleculares ITS e cox1. Foram analisados os índices parasitários: prevalência, intensidade, intensidade média, abundância, abundância média, amplitude de variação da infecção e sítio de infecção de cada espécie de parasito. Este é o primeiro registro de S. sagittifer parasitando P. isosceles e P. patagonicus, e de B. turbinella parasitando P. patagonicus.

Abstract Flounders are commercially and economically important fish. A total of 120 specimens of flounders (60 Paralichthys isosceles, 30 Paralichthys patagonicus and 30 Xystreurys rasile) were collected off the coast of the state of Rio de Janeiro, Brazil. The fish were measured, necropsied and filleted, and then had their organs investigated for acanthocephalans. Taxonomic identification of the parasites was based on morphological, morphometric and genetic characters. Paralichthys isosceles and P. patagonicus were parasitized by juveniles of Serrasentis sagittifer, Bolbosoma turbinella, Corynosoma australe and C. cetaceum; Xystreurys rasile was parasitized by C. australe. Genetic characterization confirmed the identification of specimens of Bolbosoma turbinella and Corynosoma australe, as demonstrated by phylogenetic analyses using both ITS and cox1 molecular targets. Parasite indices of prevalence, intensity, mean intensity, abundance, mean abundance, and range of infection, as well as infection site, were evaluated for each parasite species. This is the first report of S. sagittifer parasitizing P. isosceles and P. patagonicus, and B. turbinella parasitizing P. patagonicus.

Resumo Priacanthus arenatus é um peixe que ocorre nas águas do Atlântico ocidental com poucos relatos de parasitimo. Este estudo objetivou relatar as características histológicas causadas pelas larvas de H. deardorffoverstreetorum em P. arenatus. Entre julho e dezembro de 2013, 30 espécimes de P. arenatus foram obtidas de mercados de peixes das cidades de Niterói e Rio de Janeiro, Estado do Rio de Janeiro, Brasil. Fragmentos de baço, fígado, parede do estômago e mesentério contendo nódulos foram extraídos para estudo histopatológico. Foi observado através de análise histológica que esses nódulos eram constituídos por uma cápsula de tecido conjuntivo, onde se localizavam os parasitas viáveis, com infiltrado inflamatório granulomatoso, constituído, predominantemente, por macrófagos e linfócitos e por porção central de material amorfo acelular, formado por lâminas concêntricas, ligeiramente basofílico, contendo túneis e, por vezes, restos parasitários. A presença de túneis no material amorfo acelular dos nódulos analisados histologicamente sugerem que as larvas se localizam inicialmente no centro do granuloma e depois migram para a superfície do mesmo.

Abstract Priacanthus arenatus is a fish that occurs in the waters of the western Atlantic Ocean and has few records of parasitism. This study aimed to report histological changes caused by the larvae of Hysterothylacium deardorffoverstreetorum. Between July and December, 2013, 30 samples of P. arenatus were obtained from fish markets in the cities of Niterói and Rio de Janeiro, state of Rio de Janeiro, Brazil. Fragments of spleen, liver, stomach wall and mesentery tissues containing nodules and free parasites were extracted to histopathological study. Through histological analysis it was verified that these nodules consisted of connective tissue capsules, in which the parasites were located, with granulomatous inflammation mainly comprised of macrophages and lymphocytes. These nodules also consisted of a central portion of acellular amorphous material, formed by concentric layers, which was slightly basophilic and contained tunnels and, sometimes, parasite debris. The presence of tunnels in acellular amorphous material suggests that the larvae are initially located at the center of the nodules and then they migrate to the surface.

Resumo Em novembro de 2014 e maio de 2015, foi coletado um total de 44 espécimes de pescada branca, Plagioscion squamosissimus, sendo 30 na Baía de Marajó e 14 no Rio Tapajós, Estado do Pará, Brasil, com o objetivo de pesquisar a presença de nematoides anisaquideos e fornecer os índices parasitários, assim como os sítios de infecção, devido a sua importância na inspeção sanitária. Encontrou-se um total de 69 larvas de Anisakis sp., sendo 16 em 7 peixes coletados da Baía de Marajó e 53 larvas em 4 peixes do Rio Tapajós. Os índices parasitários desses nematoides coletados dos peixes da Baía de Marajó apresentaram prevalência (P) de 23%, intensidade média (IM) de 2,28, abundância média (AM) de 0,53, amplitude de variação da intensidade de infecção (AI) de 1-4 e sítio de infecção (SI) o mesentério; e os do Rio Tapajós P = 28%, IM = 13,2, AM = 3,8, AI = 1-22 e SI = mesentério e intestino. Para auxiliar na identificação taxonômica foram utilizadas imagens obtidas dos espécimes por microscopia ótica com sistema de contraste interferencial de Nomarski e microscopia eletrônica de varredura. Esse é o primeiro registro de Anisakis sp. parasitando P. squamosissimus.

Abstract In November 2014 and May 2015, a total of 44 specimens of the South American silver croaker Plagioscion squamosissimus were collected: 30 in Marajó Bay and 14 in the Tapajós River, state of Pará, Brazil. The aim was to investigate the presence of anisakid nematodes and determine their parasitism indices and sites of infection, because of their importance regarding health inspection. Sixty-nine Anisakis sp. larvae were found; among them, 16 larvae in seven fish collected in Marajó Bay and 53 larvae in four fish in the Tapajós River. The parasitism indices of the nematodes collected from the fish in Marajó Bay comprised prevalence (P) of 23%, mean infection intensity (MI) of 2.28, mean abundance (MA) of 0.53, range of infection (RI) of 1-4, and infection site (IS) in the mesentery. The fish from the Tapajós River showed P = 28%, MI = 13.2, MA = 3.8, RI = 1-22, and IS = mesentery and intestine. To assist in taxonomic identification, images of the specimens obtained through optical microscopy with Nomarski's interferential contrast system and scanning electron microscopy were used. This is the first record of Anisakis sp. parasitizing P. squamosissimus.

Foram observados 90 exemplares de P. squamosissimus, capturados com apetrechos de pesca no distrito de Outeiro, estado do Pará. Os animais foram acondicionados em sacos plásticos com água do habitat e aeração artificial, transportados vivos até o Laboratório de Pesquisa Carlos Azevedo (LPCA), em Belém-PA. Foram anestesiados, eutanasiados e necropsiados; pequenos fragmentos da musculatura epi e hipoaxial foram retirados para observação, a fresco e para histologia em microscopia de luz (ML). Em 100% dos exemplares analisados, foi observada a presença de pseudocistos parasitários entremeados, dentro e entre as fibras musculares estriadas esqueléticas, onde observou-se a presença de esporos de formato pseudoquadrado e/ou estrelado, com quatro valvas e quatro cápsulas polares, sendo identificados pela sua morfologia como pertencentes ao gênero Kudoa. Este é o primeiro relato de Kudoa em P. squamosissimus na Amazônia, Pará, Brasil.

Ninety specimens of Plagioscion squamosissimus captured using fishing tackle in the Outeiro district, state of Pará, were examined. Fish were placed in plastic bags containing water, under conditions of artificial aeration, and transported live to the Carlos Azevedo Research Laboratory (LPCA), in Belém, Pará. They were anesthetized, euthanized and necropsied; small fragments of the epaxial and hypaxial muscles were removed for examination of fresh histological sections by means of optical microscopy. In 100% of the specimens analyzed, parasitic pseudocysts were seen to be interspersed within and between the skeletal muscle. These contained pseudoquadrate and/or star-shaped spores that presented four valves and four polar capsules, which were identified from their morphology as belonging to the genus Kudoa. This is the first report of Kudoa in P. squamosissimus in the Amazon region, Pará, Brazil.

De Fevereiro a Agosto de 2012, trinta espécimes de peixe galo, Selene setapinnis, foram adquiridos de mercados locais em Niterói, Estado do Rio de Janeiro, Brasil, com o objetivo de analisá-los quanto à presença de nematoides anisaquídeos, estabelecendo seus índices parasitários e sítios de infecção, devido a sua importância na inspeção sanitária. Do total de sessenta larvas de nematoides, pelo menos duas espécies foram encontradas: nove larvas de Terranova sp., Anisakidae, com prevalência (P) de 13,3%, intensidade média (IM) de 2,25, abundância média (AM) de 0,30, e amplitude de variação da intensidade de infecção (AI) de 1 a 6; e 51 larvas de Hysterothylaciumfortalezae, Raphidascarididae, com P = 26,7%, IM = 6,40, AM = 1,70, e AI = 1 a 17. Os sítios de infecção para Terranova sp. foram o mesentério e a serosa do fígado; e para H. fortalezae, os sítios de infecção foram o mesentério, cavidade abdominal e serosa do fígado. Novos dados morfológicos das estruturas externas, principalmente da extremidade posterior de H. fortalezae, são evidenciados por microscopia eletrônica de varredura. Este é o primeiro relato de H. fortalezae parasitando S. setapinnis.

Between February and August, 2012, thirty specimens of Atlantic moonfish, Selene setapinnis, were purchased in local markets in Niterói, State of Rio de Janeiro, Brazil, with the aim of analyzing the presence of anisakid nematodes, establishing their rates of parasitism and infection sites, due to importance in the sanitary inspection. A total of sixty nematode larvae, belonging to at least two species were found: nine larvae of Terranova sp., Anisakidae, with prevalence (P) of 13.3%, mean intensity (MI) of 2.25, mean abundance (MA) of 0.30 and range of infection intensity (RI) from 1 to 6; and 51 larvae of Hysterothylaciumfortalezae, Raphidascarididae, with P = 26.7%, MI = 6.40, MA = 1.70, and RI = 1-17. The infection sites for Terranova sp. were the mesentery and liver serosa; and for H. fortalezae, the infection sites were the mesentery, abdominal cavity and liver serosa. New morphological data from scanning electron microscopy, on the external structures of H. fortalezae (mainly at the posterior end), are presented. This is the first report of H. fortalezae parasitizing S. setapinnis.

O filo Myxozoa Grassé, 1970, consiste em um grupo heterogêneo de cerca de 50 gêneros que são disseminados em todo o mundo em uma grande variedade de meios aquáticos. No presente estudo, quarenta e três espécimes de Pimelodus ornatus foram coletados a partir de uma área adjacente à cidade de Cachoeira do Arari, na Ilha do Marajó, no Estado do Pará, em 2013. À análise macroscópica verificou-se a presença de plasmódios esbranquiçados, localizados no músculo cardíaco e também na região entre o bulbus arteriosus e o atrium cordis. A análise microscópica dos tecidos parasitados revelou esporos que eram tipicamente piriformes, com a porção anterior um pouco mais estreita do que a extremidade posterior, sendo suas válvulas simétricas. A prevalência do parasitismo observada foi de 13,9% (6/43). Esta nota de pesquisa relata a primeira ocorrência de Myxobolus como um parasita do coração no peixe teleósteo P. ornatus, na Região Amazônica e, confirma a ocorrência de miocardite secundária causada por esse parasitismo. A raridade da ocorrência de Myxobolus sp. neste tecido, associado a outras características morfológicas dos esporos no peixe, sugere que é uma espécie não descrita.

The phylum Myxozoa Grassé, 1970, consists of a heterogenous group of around 50 genera that are worldwide disseminated in a wide variety of aquatic media. In the present study, 43 specimens of Pimelodus ornatus were collected from an adjacent area to the Cachoeira do Arari municipality on Marajó Island, in the Brazilian state of Pará, in 2013. Macroscopic analysis showed the presence of whitened plasmodia located in the cardiac muscle and also in the region between the bulbus arteriosus and atrium cordis. Microscopic analysis on the parasitized tissues revealed spores that were typically piriform, with the anterior portion slightly narrower than the posterior end. The spore valves were symmetrical. The present species is placed in the genus Myxobolus Butschli, 1882, because of the presence of a pair of equal polar capsules in each spore. The prevalence of parasitism observed was 13.9% (6/43). This research note reports the first occurrence of Myxobolus as a parasite of the heart in the teleostean fish P. ornatus in the Amazon region and confirms the occurrence of secondary myocarditis in this fish, caused by parasitism by Myxobolus sp. The rarity of this parasitic species of Myxobolus at this tissue site, associated with other spore morphology characteristics in the fish, suggests that it is an undescribed species.

No presente estudo, o cestóide Pterobothrium crassicolle Diesing, 1850 (Trypanorhyncha) é descrito parasitando espécimes do Peixe-dragão (Gobioides broussonnetii Lacepède, 1800), coletados no estuário do rio Paracauari na Ilha de Marajó no Norte do Estado do Pará, entre janeiro de 2009 e dezembro de 2010. Amostras de tecidos foram analisadas e blastocistos contendo larvas plerocercóides foram identificados. Estas larvas foram processadas para microscopia eletrônica de varredura. Sessenta espécimes de G. broussonnetii foram analisados, e P. crassicolle foi encontrado em 48 indivíduos (80%). Este é o primeiro registro de P. crassicolle parasitando o Peixe-dragão, G. broussonnetii.

In the present study, the cestoid Pterobothrium crassicolle Diesing, 1850 (Trypanorhyncha), was observed parasitizing specimens of the violet goby (Gobioides broussonnetii Lacepède, 1800) collected from the estuary of the Paracauarí River on Marajó Island in the north of the Brazilian state of Pará, between January 2009 and December 2010. Tissue samples were analyzed, which led to identification of blastocysts containing plerocercoid larvae. These larvae were processed for scanning electron microscopy. Sixty G. broussonnetii specimens were dissected, and P. crassicolle was found in 48 (80%) of them. The violet goby,G. broussonnetii, is a new host for P. crassicolle.