Community ecology of the metazoan parasites of red porgy, <em>Pagrus pagrus</em> (L., 1758) (Osteichthyes, Sparidae), from the coastal zone, state of Rio de Janeiro, Brazil

Abstract

Ninety specimens of red porgy, Pagrus pagrus (Linnaeus, 1758) (Osteichthyes: Sparidae) collected from the coastal zone of the State of Rio de Janeiro, Brazil (21-23^º S, 41-45^ºW), from October 1998 to March 2000, were necropsied for parasite studying. All fish were parasitized by metazoan. Twenty-two species of parasites were collected. The nematodes were 59% of the total parasitic specimens number. Contracaecum sp. larvae were the dominant species with highest prevalence and abundance. Abundance and prevalence of cymothoid isopod were positively correlated with host total length, while the prevalence of Parahemiurus merus (Linton) and Polymorphus sp. were negatively correlated with host total length. The host gender did not influence any parasite species prevalence or abundance. The mean diversity in the P. pagrus infracommunities was H=0.306±0.119, with no correlation with the host’s total length and no significant difference between male and female fish. Three pairs of species shared a significant positive covariation, and two pairs shared significant positive association between their abundances and prevalences, respectively. Negative parasite species association or covariation were not found. Qualitative similarity was observed between the ectoparasite infracommunities of P. pagrus, at the genus level, with other sparid fishes of the world.