Diet of striped sea bream Lithognathus mormyrus (Sparidae) from eastern central Adriatic Sea
The diet of striped sea bream, Lithognathus mormyrus (Linnaeus, 1758), from the central Adriatic Sea, was investigated with respect to fish size and seasons. Stomach contents of 524 specimens, total length (TL) from 12.8 to 31.7 cm, collected by trammel bottom nets and gill nets from January to December 2008, were analysed. The overall percentage of empty stomachs (17.7%) evidenced variation with seasons, maximum during winter (30.0%) and minimum during summer (8.3%). The prey belong to eight major groups: Gastropoda, Bivalvia, Polychaeta, Decapoda, Amphipoda, Copepoda, Echinodermata and Teleostei. Bivalves were the most important ingested prey in all seasons in the length class from 16 to 26 cm TL. Small prey like amphipods and copepods constituted the main prey of fish less than 16 cm TL. Conversely, the proportion of decapods and teleosts increased in the largest size class (> 26 cm TL). Bivalves, Dosinia lupinus (%IRI = 6.8) and Telinella pulchella (%IRI = 3.1) and a decapod, Liocarcinus depurator (%IRI = 2.6), were the most frequent prey. Diet composition showed little seasonal variation; bivalves were the most important prey in all seasons, but especially during winter. The lowest feeding frequency recorded in winter could be related to lower sea temperature. Striped sea bream is an active seeking bottom feeder whose diet consists of diverse benthic groups, with wide range of size and morphology.