Resumo Este estudo relata Kudoa spp. (Myxozoa, Multivalvulida) de espécies de peixes Lutjanus analis, Bagre marinus, Aspistor luniscutis e Lutjanus jocu que foram capturados na costa litorânea de Aracaju, Estado de Sergipe, Brasil. Os parasitas formavam plasmódios ovais rodeando o esófago em L. analis, enquanto que nas espécies B. marinus, A. luniscutis e L. jocu formavam plasmódios alongados no interior das fibras musculares. Fenômenos de liquefação do músculo do hospedeiro não foram observados. O presente estudo proporciona uma descrição morfológica e morfométrica de cada parasita, sendo feita uma comparação com todas as espécies conhecidas em todo mundo. A inexistência de dados moleculares prejudica a identificação específica dos parasitas. A importância destes parasitas é discutida e a necessidade de mais estudos relacionados a infecções em peixes brasileiros é enfatizada por causa do alto impacto econômico de algumas espécies de Kudoa que causam liquefação nos músculos dos hospedeiros e tornam estes peixes impróprios para consumo.

Abstract This study reports on Kudoa spp. (Myxozoa, Multivalvulida) from the fish species Lutjanus analis, Bagre marinus, Aspistor luniscutis and Lutjanus jocu, which were caught in Aracaju, state of Sergipe, Brazil. The parasites formed oval plasmodia around the esophagus of L. analis, and elongated plasmodia inside the skeletal muscle of B. marinus, A. luniscutis and L. jocu. Host myoliquefaction was not observed in all the cases studied. The current study provides a morphological and morphometric description of each parasite as well as a comparison with all the species described worldwide. Lack of molecular data impaired specific identification of the parasites. The importance of these parasites is discussed and the need for further studies on infections in Brazilian fish is emphasized because of the high economic impact of some Kudoa species which cause liquefaction in hosts’ muscles and render these fish unsuitable for consumption.

O objetivo do presente trabalho foi avaliar a fauna parasitária de quatro espécies de peixes ornamentais capturados no rio Chumucuí, no município de Bragança-PA. Foram coletados um total de 307 peixes pertencentes a 4 espécies, sendo elas:Moenkhausia sanctaefilomenae (olho de fogo, n = 23),Carnegiella strigata (borboleta, n = 37),Chilodus punctatus (cabeça-para-baixo, n = 7) e Astyanax bimaculatus (lambari, n = 240) coletados de junho de 2006 a dezembro de 2007. Foram observados 3 taxa parasitando os peixes: monogenéticos nas brânquias, nematóides (larvas deCapillaria sp. e Contracaecum sp.) no trato digestório e fígado e acantocéfalos (Quadrigyrus torquatus, Q. brasiliensis e Q. nickoli) no estômago e intestino. Astyanax bimaculatus apresentou maior prevalência de acantocéfalos na estação chuvosa, menor prevalência de nematóides na estação seca. Discute-se a eventual importância destes parasitas na exportação de peixes ornamentais.

The objective of the present study was to evaluate the parasite fauna of four species of ornamental fish collected in the Chumucuí River, municipality of Bragança, Pará, Brazil. From June 2006 to December 2007. Fishes (n=307) belonging to four species were collected, including 23 specimens of Moenkhausia sanctaefilomenae (redeye tetra), 37Carnegiella strigata (marbled hatchetfish), 7Chilodus punctatus (spotted headstander), and 240Astyanax bimaculatus (twospot astyanax). The parasites found belonged to three taxa: monogeneans in the gills, nematodes (larvae ofCapillaria sp. and Contracaecum sp.) in the digestive tract and liver and acanthocephalans (Quadrigyrus torquatus, Q. brasiliensis and Q. nickoli) in the stomach and intestine. Astyanax bimaculatus presented higher prevalence of acanthocephalans in the wet season, and lower prevalence of nematodes in the dry season. The possible importance of these parasites in the exportation of ornamental fish is discussed.

O objetivo desse trabalho foi registrar a primeira ocorrência sazonal do acantocefala Quadrigyrus nickoliSchmidt & Hugghins, 1973(Quadrigyridae) no peixe “Mato Grosso”,Hyphessobrycon eques Steindachner, 1882 (Characidae), capturados no Rio Chumucuí, região Bragantina, Pará, Brasil. Os peixes foram coletados no período de julho∕2006 a junho∕2007 e examinados com técnica padrão para detecção de parasitas. Um total de 75 parasitas foram encontrados no estômago e intestino. Dos 83 peixes capturados (50 na estação seca e 33 na chuvosa), 22 estavam parasitados por cistacantos de Quadrigyrus nickoli. No presente trabalho discute-se a importância do H. eques como hospedeiro paratênico para Quadrigyrus nickoli. Os presentes dados constituem o primeiro estudo sobre a biologia e a infecção de Q. nickoli na Amazônia oriental.

The objective of this work was to report the first seasonal occurrence of the acanthocephalan Quadrigyrus nickoliSchmidt & Hugghins, 1973(Quadrigyridae), in the “Mato Grosso”Hyphessobrycon eques (Characidae) (Steindachner, 1882), collected from the Chumucuí River, state of Pará, Brazil. The fish were collected between July 2006 (rainy season) and June 2007 (dry season) and were examined for parasites using pattern techniques. A total of 75 parasites were found in the stomach and intestine. Among 83 fish examined (50 in the dry season and 33 in the rainy season), 22 were parasitized by cystacanths of Q. nickoli. The importance of H. eques as a paratenic host for Q. nickoli is discussed. This is the first study on the biology of and infection by Q. nickoli occurring in the eastern Amazon region.

The objective of this work was to evaluate the host/parasite relationship of nematodes in Macrodon ancylodon. Ninety seven fishes (50 in wet season and 47 in dry season) were weighed (167.1 ± 109.9g) and measured (28.3 ± 5.2cm). Only twelve specimens were not infected by any parasites and the prevalence of infection was 87.6%. The highest prevalence values were observed in August and September (dry season, 100%). The stomach was the most infected organ during the whole months (prevalence of 64.2%, and mean intensity of 4.6±7.8 parasites/fish), and the medium intestine showed the lowest infection (prevalence 27.3% and mean intensity 2.5±2.1 parasites/fish). The nematodes were identified as Raphidascaris sp., Goezia sp. and Cucullanus sp. Only the male and juvenile fishes could be presented different values of infection according to rainfall, being more infected in August to October. The female hosts presented higher values of abundance and mean intensity of infection (p<0.01) throughout the year.