Diet of the European flying squid Todarodes sagittatus (Cephalopoda : Ommastrephidae) in the Balearic Sea (western Mediterranean)

Stomach contents of Todarodes sagittatus caught by trawlers working from 10 0 to 800 m depth in the Balearic Sea (western Mediterranean) were studied. From the 348 stomachs examined (153 males and 195 females) 33.62% were empt y (39.21% in males and 29.74% in females). The diet of the squid was compos ed of 58 different prey items belonging to four major groups: Osteichthya, Crustacea, Cephlalopoda and Chondrichthya. Osteichthyes, crustaceans and ce phalopods were the most common prey, with a frequency of occurrence value o f 84.85, 48.92 and 29.87% respectively. A change in the diet as the squid g rows was observed, since juveniles feed basically on fishes while adults pr ey more actively on crustaceans. Analysis of the diet by size-classes refle cted an ontogenetic migration to deeper waters since, parallel to the incre ase of size, a raise in the percentage of prey species inhabiting deeper wa ters was detected. Cannibalism was quite frequent, since T. sagittatus was the second most common cephalopod prey. Females had higher fullness-weight index and lower emptiness index than males, which reflects their major ener getic demand for egg production.