Régime alimentaire de la dorade coryphène Coryphaena hippurus (Coryphaenidae) des côtes tunisiennes
Diet of dolphinfish Coryphaena hippurus (Coryphaenidae) from the Tunisian coast
The stomach contents of 178 individuals of Coryphaena hippurus, of fork length (LF) between 18 and 82 cm and weight between 71 and 5880 g, are analyzed. The fishes were caught between July and December 2010. The results show that it is a pelagic, predatory and opportunistic species. Teleost fish are favourite preys, and crustaceans, secondary or incidental preys. Juveniles (< 25 cm FL) exclusively feed on pelagic fish, Clupeidae and Engraulidae, while older dolphinfish (25-50 cm FL) feed on epipelagic fish, Scombridae and Belonidae. Sub-adults (> 50 cm FL) feed on benthic fish, Sparidae, Congridae, Mugilidae and Dactylopteridae. Crustaceans are mainly represented by Amphipoda (Hyperiidae) for young juveniles under 25 cm FL, by Euphausiacae in the size class 25-50 cm FL and Decapoda for specimens over 50 cm FL. Ingesting typically benthic species, as the cephalopoda Sepia officinalis, shows the high hunting performance and opportunism of the dolphinfish that is able to find its prey on the seafloor.