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.

Abstract The Helminthological Collection of the Oswaldo Cruz Institute is the biggest in Latin America and it is among the largest collections at worldwide reference level, with around 40,000 sets of specimens and approximately one million individual specimens. It contains helminths parasites of vertebrate and invertebrate animals that form part of the fauna of Brazil and other countries. The samples comprise holotypes, paratypes and representative specimens of Platyhelminthes, Acanthocephala, Nematoda and other non-helminth phyla, such as Annelida and Arthropoda. Some of the samples preserved in liquid media were found to have dried out. This made it impossible to analyze these samples morphologically for taxonomic purposes. The aim of this study was to test techniques used for rehydration of the tegument of specimens that had been found to have dried out and present protocols for such techniques. A total of 528 specimens that either no longer were immersed in preservatives or had already dried out were analyzed: 96 digenetic trematodes, 45 cestodes, 22 acanthocephalans, 357 nematodes, four hirudineans and four pentastomid crustaceans. The technique of rehydration using only distilled water on the specimens proved to be efficient for recovering tegument malleability, for all samples analyzed in this present study.

Resumo A Coleção Helmintológica do Instituto Oswaldo Cruz é a maior da América Latina e está entre as maiores coleções de referência mundial, com cerca de 40.000 lotes e, aproximadamente, um milhão de espécimes. Seu acervo reúne helmintos parasitos de animais vertebrados e invertebrados da fauna brasileira e de outros países. Seus exemplares são holótipos, parátipos e espécimes representativos de parasitos, pertencentes aos filos Platyhelminthes, Acanthocephala, Nematoda e, ainda alguns espécimes não-helmintos, pertencentes aos filos Annelida e Arthropoda. Parte das amostras preservadas como material líquido foram encontradas dessecadas. Esta condição torna as amostras inviáveis para análise morfológica para propósitos taxonômicos. Portanto, o objetivo deste trabalho foi testar técnicas usadas na reidratação do tegumento dos espécimes que se encontram dessecados e apresentar seus protocolos. Foram analisados 528 lotes, cujos espécimes encontravam-se sem conservantes ou já dessecados: 96 trematodeos digenéticos, 45 cestoides, 22 acantocéfalos, 357 nematoides, quatro hirudíneos e quatro crustáceos pentastomídeos. A técnica de reidratação dos espécimes, utilizando-se apenas água destilada, mostrou-se eficiente na recuperação da maleabilidade tegumentar de todas as amostras trabalhadas no presente estudo.

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 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.

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 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.

Abstract Abstract: Trichiurus lepturus (Actinopterygii, Perciformes) is a commercially and economically important fish. A total of 60 specimens of this cutlassfish were collected of the coast the municipalities of Niterói and Cabo Frio, state of Rio de Janeiro, Brazil. The fish were measured, necropsied, filleted and had their organs investigated for digenetic trematodes. Taxonomic identification was based on morphological and morphometric characters. The specimens of T. lepturus were parasitized with adult specimens of Lecithochirium monticellii. Parasite indices of prevalence, intensity, mean intensity, abundance, mean abundance, range of infection, and site of infection of parasitic species were evaluated. Notes on the taxonomy of the parasite were also included. This is the first report of L. monticellii parasitizing T. lepturus in Brazil.

Resumo O presente estudo objetivou determinar taxonomicamente as espécies de plerocercos de cestoides Trypanorhyncha encontradas na serosa intestinal das tainhas Mugil liza, através do estudo morfológico e morfométrico e indicar seus índices parasitários. Foram coletados 150 espécimes desta espécie de tainha do litoral do estado do Rio de Janeiro. Após as necropsias, os cestoides Trypanorhyncha encontrados foram fixados e preservados em montagens permanentes para permitir a análise de suas estruturas morfológicas. Os plerocercos foram identificados como Callitetrarhynchus gracilis e Pterobothrium crassicole e ambas as espécies apresentaram prevalência de 0,67%, intensidade de 1 e abundância de 0,0067, em infecções únicas. Este é o primeiro registro de cestoides Trypanorhyncha parasitando M. liza no Brasil. Quanto ao aspecto higiênico-sanitário, vale ressaltar que, embora os índices parasitários registrados tenham sido baixos, os plerocercos dessas espécies estavam visíveis a olho nu, podendo causar repugnância ao consumidor e inviabilizar a comercialização do pescado.

Abstract The aim of the present study was to identify, through morphological and morphometric analyses, the species of trypanorhynch cestodes found as plerocerci in the intestinal serosa of Mugil liza and to determine their parasitic indices. One hundred and fifty specimens of this mullet collected off the coast of the state of Rio de Janeiro were necropsied and the trypanorhynch cestodes found were fixed and preserved as whole mounts for morphological analysis. The plerocerci were identified as Callitetrarhynchus gracilis and Pterobothrium crassicole, both with a prevalence of 0.67%, an intensity of 1 and abundance of 0.0067, in single infections. This is the first record of a trypanorhynch cestode parasitizing M. liza in Brazil. Although the parasitic indexes were low, from a hygienic-sanitary perspective the plerocerci of these species are visible to the naked eye, and thus can disgust consumers and make marketing the fish unfeasible.

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 Atractis thapari Petter, 1966, um nematoide atractídeo, foi coletado parasitando o intestino grosso de jabutis, Chelonoidis carbonarius (Spix, 1824) (Cc) e C. denticulatus (Linnaeus, 1766) (Cd) no Parque Zoobotânico, município de Teresina, estado do Piauí, Brasil. A identificação taxonômica foi baseada nos caracteres morfológicos e morfométricos usando microscopias de campo claro e eletrônica de varredura. O presente estudo adiciona novas observações na morfologia, principalmente relacionadas as papilas bucais, poro excretor, deirídeos, e extremidade posterior de machos e fêmeas. Os índices parasitários de prevalência (P), intensidade média (IM), abundância média (AM) e amplitude de variação de infecção (AI) de A. thapari em ambos jabutis foram P = 100%, IM = 154.667, AM = 154.667, AI = 5.500-588.500 (Cc); P = 100%, I M= 93.639, AM = 93.639, AI = 1.000-224.500 (Cd). Este registro confirma a ocorrência de A. thapari na região Neotropical, América do Sul, Brasil, e expande a um novo hospedeiro, o jabuti C. carbonarius. É sugerido um ajuste no manejo dos hospedeiros objetivando melhora das suas condições higiênico sanitárias.

Abstract Atractis thapari Petter, 1966, an atractid nematode, was collected parasitizing the large intestine of tortoises of the species Chelonoidis carbonarius (Spix, 1824) (Cc) and C. denticulatus (Linnaeus, 1766) (Cd) (Testudinidae) in the Zoobotanical Park of the municipality of Teresina, state of Piauí, Brazil. Taxonomic identification was based on morphological and morphometrical features, and using bright-field and scanning electron microscopy. The present study adds new observations on the morphology of A. thapari, mainly relating to mouth papillae, the excretory pore, deirids, and male and female posterior ends. The parasitic indices of prevalence (P), mean intensity (MI), mean abundance (MA) and range of infection (RI) for A. thapari in these two tortoise species were: P = 100%, MI = 154,667, MA = 154,667, RI = 5,500-588,500 (Cc); P = 100%, MI = 93,639, MA = 93,639, RI = 1,000-224,500 (Cd). This report confirms the occurrence of A. thapari in Neotropical region, South America, Brazil, and extends its occurrences to a new host, the tortoise C. carbonarius. Adjustment of host management with the aim of improving hygiene and health conditions is suggested.

ABSTRACT From September 2014 to November 2015, 30 Paralichthys orbignyanus specimens were obtained from Sepetiba Bay in the municipality of Rio de Janeiro, State of Rio de Janeiro, Brazil. The fishes were necropsied and cestode larvae were recovered from the abdominal cavity, mesentery, and serosas of the stomach, intestine, spleen, liver, kidney and gonads. Nineteen fish were parasitized by a total of 90 trypanorhynch plerocerci. Based on morphological characters, these were identified as Pterobothrium crassicolle. The parasitism indices for P. crassicolle on P. orbignyanus, were 63.3% for prevalence, 4.7 for mean intensity, 3 for mean abundance and 1 to 18 for range of infection. These parasites were studied due to their importance during fish sanitary inspection, if one considers the harm that the repulsive aspect of infected fish may cause to consumers. This is the first record of P. crassicolle plerocerci parasitizing P. orbignyanus.

Resumo No presente estudo é relatado pela primeira vez Litomosoides silvai parasitando Akodon montensis coletados na região Sul do Brasil. Foram fornecidas novas informações morfológicas para algumas estruturas desta espécie de nematódeo, tais como extremidade cefálica achatada, a presença de duas papilas cefálicas dorsais, cauda das fêmeas com uma constrição na ponta da cauda, vagina em forma de “s”, espículas de característica do grupo de espécies de carinii e cauda da microfilária com constrição na ponta. Este nematódeo parasitava a cavidade torácica com uma prevalência de 10% (2/20), intensidade média de 4 (8/2) e abundância média de 0,4 (8/20), e intervalo de infecção de 2-6 espécimes por hospedeiro no Sul do Brasil. A ocorrência de L. silvai em A. montensis é um novo registro geográfico, no sul do Brasil, a noroeste do estado do Rio Grande do Sul, na ecorregião da Mata Atlântica do Alto Paraná, parte do bioma da Mata Atlântica.

Abstract In the present study, Litomosoides silvai parasitizing Akodon montensis in the southern region of Brazil is reported for the first time. New morphological information is provided for some structures of this nematode species, such as a flattened cephalic extremity, presence of two dorsal cephalic papillae, female tail with a constriction at its tip, “s” shaped vagina, spicules characteristic of the carinii species group and microfilaria tail constricted at the tip. This nematode was found parasitizing the thoracic cavity with a prevalence of 10% (2/20), mean intensity of 4 (6/2), mean abundance of 0.4 (8/20) and range of infection of 2-6 specimens per host, in southern Brazil. This occurrence of L. silvai in A. montensis is a new geographical record for southern Brazil, in the Upper Paraná Atlantic Forest ecoregion of the northwestern region of Rio Grande do Sul, which is part of the Atlantic Forest biome.

Resumo Chapiniella variabilis (Chapin, 1924), um nematoide estrongilídeo, foi coletado parasitando o intestino grosso de jabutis, Chelonoidis carbonarius (Spix, 1824) e C. denticulatus (Linnaeus, 1766) do Parque Zoobotânico, município de Teresina, estado do Piauí, Brasil. A identificação taxonômica foi baseada nos caracteres morfológicos e morfométricos usando microscopias de campo claro e eletrônica de varredura. O presente estudo adiciona novas observações na morfologia, principalmente relacionadas as papilas bucais, elementos externos e internos da coroa-foliar, poro excretor, deirídeos, e extremidade posterior de machos e fêmeas. Os índices parasitários de prevalência (P), intensidade média (IM), abundância média (AM) e amplitude de variação de infecção (AI) de C. variabilis em ambos jabutis foram P = 100%, IM = 833,3, AM = 833,3, AI = 500-1.500 (Cc); P = 100%, IM = 472,2, AM = 472,2, AI = 333-500 (Cd). Este registro aumenta a ocorrência de C. variabilis a um novo hospedeiro, C. carbonarius, e a um outro estado do Brasil, na região Neotropical da América do Sul. É sugerido um ajuste no manejo dos hospedeiros objetivando melhora das suas condições higiênico sanitárias.

Abstract Chapiniella variabilis (Chapin, 1924), a strongylid nematode, was collected parasitizing the large intestine of the tortoises Chelonoidis carbonarius (Spix, 1824) (Cc) and C. denticulatus (Linnaeus, 1766) (Cd) in the Zoobotanical Park of the municipality of Teresina, state of Piauí, Brazil. The taxonomic identification was based on morphological and morphometric features, using bright-field and scanning electron microscopy. The present study adds new observations on the morphology, mainly relating to the mouth papillae, external and internal leaf-crown elements, excretory pore, deirids and male and female posterior end. The parasitic indices of prevalence (P), mean intensity (MI), mean abundance (MA) and range of infection (RI) of C. variabilis in these two tortoise species were: P = 100%, MI = 833.3, MA = 833.3, RI = 500-1,500 (Cc); P = 100%, MI = 472.2, MA = 472.2, RI = 333-500 (Cd). This record expands occurrences of C. variabilis to a new host, C. carbonarius, and to another state in Brazil, in the Neotropical region of South America. Adjustment to host management with the aim of improving hygiene and health conditions is suggested.