The parasite–host interactions among two isopod species Cymothoa spinipalpa and Rocinela signata and five marine fish species, Chloroscombrus chrysurus, Caranx crysos, Oligoplites saliens, Lutjanus synagris and Trichiurus lepturus, are described here and registered for the first time on the coast of Bahia, north-eastern Brazil. Based on samples using different fishing techniques in different seasons from 2006 to 2009, discussions of the ecological and clinical association of these interactions are presented in this paper. Most fish species showed high prevalence indices associated with a high abundance of host fish.
