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 (%IRIa= 6.8) and Telinella pulchella (%IRIa= 3.1) and a decapod, Liocarcinus depurator (%IRIa= 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.Original Abstract: Regime alimentaire du marbre, Lithognathus mormyrus (Sparidae), en mer Adriatique centrale. Le regime alimentaire de Lithognathus mormyrus en mer Adriatique a ete etudie en fonction de la taille des poissons et de la saison. Les contenus stomacaux de 524 specimens (12,8-31,7 cm LT), captures par une petite seine de plage de janvier a decembre 2008, ont ete analyses. Au total, 93 estomacs etaient vides (17,7%). Ce pourcentage a significativement change selon les saisons, avec un nombre maximum d'estomacs vides enregistre pendant l'hiver (30,0%) et un nombre minimum enregistre pendant l'ete (8,3%). Le contenu stomacal de Lithognathus mormyrus est compose de 8 groupes principaux de proies : les mollusques gastropodes et bivalves, les annelides polychetes, les crustaces decapodes, copepodes et amphipodes, les echinodermes et les teleosteens. Les bivalves sont les proies principales, surtout parmi la classe de taille de 16-26 cm LT. Les crustaces amphipodes et copepodes sont les proies principales des individus de taille inferieure a 16 cm LT. L