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.

Resumo Um total de 132 espécimes de linguados (60 Paralichthys isosceles, 36 Paralichthys patagonicus e 36 Xystreurys rasile) foram coletados na costa do Estado do Rio de Janeiro, Brasil. Os peixes foram medidos, necropsiados e tiveram seus órgãos investigados para o encontro de trematodeos digenéticos, das famílias Hemiuridae e Lecithasteridae, e nematoides das famílias Camallanidae e Cucullanidae. A identificação taxonômica dos parasitos foi baseada nos caracteres morfológicos e morfométricos, usando-se as microscopias de campo claro e eletrônica de varredura. Os trematódeos, Lecithochirium monticellii e Aponurus laguncula, foram encontrados parasitando P. isosceles, P. patagonicus e X. rasile, enquanto os nematoides, Procamallanus (Spirocamallanus) halitrophus e Cucullanus bonaerensis, foram encontrados parasitando P. isosceles e X. rasile e P. isosceles, P. patagonicus e X. rasile, respectivamente. Os índices parasitários de prevalência, intensidade média, abundância média e amplitude de variação da intensidade de infeção, bem como os sítios de infecção foram avaliados para cada espécie de parasito. Este é o primeiro registro de P. patagonicus por L. monticellii; X. rasile por A. laguncula e P. (S.) halitrophus; e de P. isosceles e P. patagonicus por C. bonaerensis no Oceano Atlântico Sul Ocidental.

Abstract A total of 132 flounder specimens (60 Paralichthys isosceles, 36 Paralichthys patagonicus and 36 Xystreurys rasile) were collected off the coast of the state of Rio de Janeiro, Brazil. The fish were measured, necropsied, and had their organs investigated for hemiurid and lecithasterid digenean trematodes and camallanid and cucullanid nematodes. Taxonomic identification of the parasites was based on morphological and morphometric characters and was conducted using bright-field and scanning electron microscopies. The trematodes Lecithochirium monticellii and Aponurus laguncula were found parasitizing P. isosceles, P. patagonicus and X. rasile while the nematodes Procamallanus (Spirocamallanus) halitrophus and Cucullanus bonaerensis were found parasitizing P. isosceles and X. rasile and P. isosceles, P. patagonicus and X. rasile, respectively. Parasite indices of prevalence, mean intensity, mean abundance, and range of infection, as well as infection site, were evaluated for each parasite species. This study allowed to evidence the first occurrence of P. patagonicus by L. monticellii; X. rasile by A. laguncula and P. (S.) halitrophus; and P. isosceles and P. patagonicus by C. bonaerensis in the Western South Atlantic Ocean.

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.

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.

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.

Entre janeiro e agosto de 2012, 30 espécimes de Cynoscion guatucupa (Cuvier, 1830) pescados no litoral do município de Itajaí, estado de Santa Catarina, Brasil (26° 54′ 28″ S and 48° 39′ 43″ W) e comercializados no estado do Rio de Janeiro, foram investigados quanto á presença de nematóides zoonóticos. Foram encontradas 853 larvas de quatro espécies de nematóides parasitos. Três espécies pertencem á Anisakidae, sendo três larvas de Anisakis sp., com prevalência (P) de 10%, intensidade média (IM) de 1, abundância média (AM) de 0,1 e sítio de infecção (SI) o mesentério; cinco de Terranova sp., com P = 13,3%, IM = 1,25, AM = 0,17, amplitude de variação da intensidade de infecção (AI) de 1 a 2 e SI = mesentério; e sete de Contracaecum sp., com P = 6,6%, IM = 3,5, AM = 0,23, AI = 1 a 4 e SI = mesentério e cavidade abdominal. Uma espécie pertence á Raphidascarididae, sendo 838 larvas de Hysterothylacium deardorffoverstreetorum com P = 83,3%, IM = 33,52, AM = 27,93, AI = 1 a 219 e SI = mesentério, serosa do fígado e cavidade abdominal. Este é o primeiro registro de larvas de Anisakis sp. eContracaecum sp. em C. guatucupa no Brasil.

Between January and August 2012, thirty specimens of Cynoscion guatucupa (Cuvier, 1830) caught off coast of the municipality of Itajaí, state of Santa Catarina, Brazil (26° 54′ 28″ S and 48° 39′ 43″ W) and commercialized in the state of Rio de Janeiro were investigated for the presence of zoonotic nematodes. In total 853 larvae of four nematode parasite species were found. There were three species of Anisakidae: three larvae ofAnisakis sp., with prevalence (P) of 10%, mean intensity (MI) of 1.0, mean abundance (MA) of 0.1 and infection site (IS) in the mesentery; five of Terranova sp. with P = 13.3%, MI = 1.25, MA = 0.17, range of infection (RI) from 1 to 2 and IS = mesentery; and seven ofContracaecum sp. with P = 6.6%, MI = 3.5, MA = 0.23, RI = 1 to 4 and IS = mesentery and abdominal cavity. There was one species of Raphidascarididae: 838 larvae of Hysterothylacium deardorffoverstreetorum with P = 83.3%, MI = 33.52, MA = 27.93, RI = 1 to 219 and IS = mesentery, liver serosa and abdominal cavity. This is the first report of larvae of Anisakis sp. andContracaecum sp in C. guatucupa in Brazil. Hysterothylacium deardorffoverstreetorum;Anisakis sp.; Terranova sp.;Contracaecum sp.; Cynoscion guatucupa

Taking into account the difficulties of taxonomic identification of larval anisakid nematodes based on morphological characters, genetic analyses were performed, together with those usually applied, in order to identify anisakid larvae found in the flounder Paralichthys isosceles from the littoral of the state of Rio de Janeiro, Brazil. The analysis of 1,820 larvae revealed a new species, similar to Hysterothylacium MD, Hysterothylacium 2, Hysterothylacium KB and Hysterothylacium sp regarding the absence of the larval tooth, an excretory pore situated below the nerve ring level, and slender lateral alae. Moreover, the new species differs from Hysterothylacium fortalezae and Hysterothylacium reliquens with regard to the number and size of spines present on the tail end and from Hysterothylacium patagonicus by the absence of interlabia. The maximum parsimony and neighbour joining tree topologies based on the 18S ribosomal DNA gene, complete internal transcribed spacer region and cytochrome oxidase 2 (COII) gene demonstrated that the Brazilian larvae belong to Raphidascarididae and represent a unique genetic entity, confirmed as a new Hysterothylacium species. Furthermore, the new species presents COII genetic signatures and shares polymorphisms with Raphidascarididae members. This is the first description of a new anisakid species from Brazil through the integration of morphological and molecular taxonomy data.