FEEDING-HABITS OF YOUNG-OF-THE-YEAR GREATER AMBERJACK SERIOLA DUMERILI (RISSO, 1810) ALONG THE N W SICILIAN COAST/

A survey was carried out from July to December 1992 in the Gulf of Cas tellammare (N/W Sicily) in order to study the feeding habits of juveni les of the greater amberjack Seriola dumerili. Stomach content analysi s showed three different phases of predation during this period, depen ding on the size variation of the specimens. Cluster analysis suggeste d prey choice differed within three size groups. Class I (individuals up to 80 mm SL) feed mainly on the zooplankton community (Copepoda and Crustacea larvae). Class II (individuals ranging from 80 to 120 mm SL ) represent a transition stage in which fish continue to feed on zoopl ankton, but benthic and nectonic items also become important. Class II I (individuals greater than 120 SL mm) feed mainly on nectonic and nec tobenthic items. Fish belonging to the size class II showed the highes t value of niche breadth. The role of the Cymodocea nodosa system is s tressed as an energy supply of invertebrate and vertebrate food items, especially to the size class II, in which fish shift from a planktivo rous to a piscivorous diet. Further research is needed to understand b etter the feeding rhythm, food consumption and the role of benthic com munities in the diet of this species.