Diet and Feeding of Dolphin (Coryphaena hippurus) in Western Mediterranean Waters

Diet and feeding habits of Coryphaena hippurus were studied by examining the stomachs of 316 specimens, between 14 and 117 cm fork length, caught with drifting longlines and purse nets from May 1990 to November 1991 off the island of Majorca (western Mediterranean). C. hippurus preyed on a wide variety of pelagic species, mainly teleost fishes. Dietary comparison between size classes revealed significant changes in diet, with crustaceans and cephalopods playing an important role in the diet of young and adult specimens, respectively. Diel changes in feeding activity indicated that C. hippurus is a visual predator, feeding during sunlight hours. However, the presence of some mesopelagic prey species, which undergo daily vertical migrations, seemed to indicate that this species also feeds during the night. The positive correlation between the size of C. hippurus and the size of two ommastrephids and two fish prey species, showed little evidence of any selectivity in feeding behavior. The large proportion of epipelagic prey indicated that this species feeds mainly in the sub-surface layers of oceanic waters, and is one of the top predators in the western Mediterranean pelagic ecosystem.