The metazoan parasite community of the barred grunt Conodon nobilis (Actinopterygii: Haemulidae) from the coast off Rio de Janeiro, southeastern Brazil.

The barred grunt, Conodon nobilis (Linnaeus, 1758), is one of the most important marine-estuarine fish along the Brazilian coast. The present study evaluated the parasite fauna of this haemulid fish along the Southern Atlantic coast. From September 2010 to July 2011, a total of 100 specimens of C. nobilis from Angra dos Reis, Rio de Janeiro State, Brazil (23°01'21"S, 44°19'13"W), were examined. Ninety-seven individuals were parasitized by at least one species of metazoan, with a mean of 4.50 ± 3.54 parasites per fish. Eighteen species of parasites were collected: eight copepods, four digeneans, two cestodes, one acanthocephalan, one aspidogastrean, one isopod and one monogenean. The copepod Lernanthropus rathbuni was the most abundant and dominant species, accounting for 17.77% of all parasite specimens collected. Caligus haemulonis was the most prevalent. Prevalence and abundance of Acantholochus lamellatus and L. rathbuni tended to be higher in smaller fish, whereas those of Torticaecum sp. were higher in larger fish. The mean abundance of C. haemulonis was significantly higher in male hosts. A negative association was observed between two species of ectoparasites. The parasite community of C. nobilis was characterized by dominance of copepods, which can be related to host's schooling behavior.