Thunnus atlanticus is of great commercial importance in Brazil, but infections caused by helminth parasites can reduce its commercial value. In this paper, 15 species of Digenea and three of Monogenoidea were recovered from 61 specimens of T. atlanticus collected from the coastal zone of the State of Rio de Janeiro. Species of the family Didymozoidae were the dominant species, with highest prevalence and abundance values. The parasites showed the typical aggregated distribution pattern, except for Nasicola brasiliensis, which had an aleatory distribution pattern. Prevalence and abundance of Didymosulcus philobranchiarca, Didymocystis lamotheargumedoi and Didymosulcus wedli and prevalence of Koellikerioides internogastricus were positively correlated with the total length of the host. The abundance of Coeliotrema thynni was negatively correlated with total length of the host. New hosts re...

Four species of scombrid fishes (Perciformes) from the coastal zone of Rio de Janeiro, Brazil, wereexamined for helminth parasites. These are Thunnus albacares (Bonnaterre, 1788), Thunnus atlanticus(Lesson, 1831), Thunnus obesus (Lowe, 1839) and Euthynnus alletteratus (Rafinesque, 1810). Threespecies of the genus Koellikerioides Yamaguti, 1970: K. apicalis Yamaguti, 1970, K. externogastricusYamaguti, 1970 and K. intestinalis Yamaguti, 1970, were recorded from the gill raker, the outer musclelayer of the stomach wall and the inner surface of the small intestine, respectively. Originalmeasurements, parameters of infection and original figures are presented. K. apicalis and K. intestinalisshowed the typical aggregated distribution pattern. Statistical analysis showed that there was asignificant negative correlation between the total lengths of E. alletteratus and the prevalence of K.intesti...

Para el presente estudio, fueron adquiridos 276 atunes, entre enero de 2000 y diciembre de 2002, en mercados de peces, siendo 107 ejemplares de Katsuwonus pelamis (Linnaeus, 1758), 5 Auxis thazard (Lacepède, 1800), 92 Thunnus albacares (Bonnaterre, 1788), 30 Thunnus atlanticus (Lesson, 1830), 25 Thunnus obesus (Lowe, 1839), y 17 Thunnus thynnus (Linnaeus, 1758) pescados en el municipio de Cabo Frio, Estado de Rio de Janeiro, Brasil. Cincuenta y seis (20,28%) de los peces fueron parasitados por lo menos con una especie de parásito. Se colectaron un total de 196 nemátodos larvarios y fueron identificados como: Anisakis (Rudolphi, 1809, det. Krabbe, 1878), A. physeteris Baylis 1923, Contracaecum sp. y Raphidascaris sp. Este estudio es el primer registro en Brasil con nuevos registros para los hospederos de A. simplex en T. albacares, T. atlanticus y T. obesus, de A. physeteris en T. alba...