Community ecology of the metazoan parasites of the tomtate Grunt Haemulon Aurolineatum Cuvier, 1830 off Rio de Janeiro, Southeastern Brazil

Abstract

The present study provides the first ecological assessment of the metazoan parasite community of the tomtate grunt, Haemulon aurolineatum Cuvier, 1830 (Actinopterygii: Haemulidae), from the southeastern Brazilian coast. Between May 2022 and February 2023, 100 specimens were collected from Angra dos Reis, Rio de Janeiro, Brazil, and examined for metazoan parasites. A total of 284 parasite specimens belonging to 19 species were recovered, including digeneans, monogeneans, nematodes, copepods, and acanthocephalans. Adult endoparasites predominated in the parasite community, accounting for 91.54% of all collected specimens. The nematode Procamallanus sp. was the most prevalent, abundant, and dominant parasite species, whereas the copepod Ceratocolax tavaresi Casanova, Paschoal & Luque, 2023 showed the highest mean relative dominance. Three parasitic species exhibited an aggregated distribution pattern. The abundance of Procamallanus sp. was positively correlated with host total length, while no significant relationship was observed between host size and overall parasite abundance, richness, or diversity. Significant differences in parasite diversity were detected between male and female hosts. Interspecific association analyses revealed a tendency toward a positive association between Procamallanus sp. and Genolopa ampullacea Linton, 1910, although without statistical significance. The parasite fauna recorded herein expands the known host range of several taxa, including Ceratocolax tavaresi, Dichelyne sp., Monorchis sp., and Prosorhynchus ozakii Manter, 1934. These findings provide baseline ecological data for future comparative and monitoring studies involving haemulid fishes and marine environmental quality along the Brazilian coast.