Persistent companionships: The parasitic copepod community of the dolphinfish Coryphaena hippurus on the Ecuadorian coast

The common dolphinfish, Coryphaena hippurus, is an important and widespread fishing resource in tropical and subtropical latitudes. It harbors a diverse array of parasitic copepods, but data on their infection indices are quite limited worldwide. We analyzed its parasitic copepod community and infection indices based on the examination of 615 individuals of C. hippurus landed monthly on the coast of Ecuador, over a period of 1 year. Both the opercular cavities and gills of the sampled fish were examined for parasitic copepods, of which nine taxa were recorded: Brachiella quaternia, Caligus belones, C. bonito, C. coryphaenae, C. productus, Euryphorus brachypterus, E. nordmannii, Lepeophtheirus sp., and Lernaeenicus sp. The finding of five of these species (i.e., B. quaternia, C. belones, C. productus, E. brachypterus, and E. nordmannii) represents new geographic records. C. bonito showed the highest prevalence (83%), mean abundance (5.46 ± 4.99), and mean intensity (6.57 ± 4.99), followed by B. quaternia (prevalence = 32%, mean abundance = 1.89 ± 5.66, mean intensity = 5.89 ± 5.71). The infection indices of C. bonito decreased with increasing host length and were higher in females than in males. The parasitic copepod community of common dolphinfish in this study was similar to communities in other parts of its geographic distributional range, including the Atlantic Ocean, the Mediterranean Sea, and the Eastern Pacific, consistently dominated by a generalist parasitic species. This is the first and most detailed quantitative evaluation of the parasitic copepods associated with the dolphinfish and updates the extant parasitological data for this host.