Community ecology of the metazoan parasites of the grey triggerfish, Balistes capriscus Gmelin, 1789 and queen triggerfish B. vetula Linnaeus,1758 (Osteichthyes: Balistidae) from the State of Rio de Janeiro, Brazil.

Sixty-six specimens of grey triggerfish Balistes capriscus Gmelin, 1788 and thirty specimens of queen triggerfish B. vetula Linnaeus, 1758 (Osteichthyes: Balistidae) collected from the coastal zone of the State of Rio de Janeiro (21-23 degrees S, 41-45 degrees W), Brazil, from April 2001 to May 2003, were necropsied to study their metazoan parasites. All fish were parasitized by at least one parasite species. Twenty-seven parasites species were collected: 22 in B. capriscus and 15 in B. vetula. Ten parasite species were common to the two host species. Balistes capriscus and B. vetula were a new host record for 16 and seven parasite species, respectively. Hypocreadium biminensis and Taeniacanthus balistae were recorded for the first time in Brazil. The copepod T. balistae and the nematode Contracaecum sp. were the dominant species with highest parasitic prevalence and abundance in the parasite community of B. capriscus and B. vetula, respectively. The metazoan parasites of B. capriscus and B. vetula showed typical aggregated pattern of distribution. The infracommunities of adult endoparasites showed highest values of mean abundance and parasite species richness. The parasite species richness, the total number of specimens and the mean Berger-Parker's index of the infracommunities of B. capriscus and B. vetula showed significant differences.