Diet of juvenile Pagrus pagrus (Sparidae) from sandy bottoms of the southern Tyrrhenian Sea

Feeding habits of juvenile red porgy Pagrus pagrus collected from a sandy bottom off Capo d'Orlando (southern Tyrrhenian Sea) were studied from 1994 to 1996. A total of 134 specimens were caught by boat seine and their guts preserved. Food items were identified, counted and weighted. Frequency of occurrence (%F), abundance (%N) and weight (%W) were used to calculate the index of relative importance (IRI) for each prey category. The analysis of prey items led to the identification of 78 mostly epibenthic taxa with crustaceans emerging as the dominant group, followed by molluscs and teleosts. Prey were neither partitioned by weight nor by abundance in the size range of fish examined, as confirmed by NPMANOVA performed on three fish size classes. Despite the large number of taxa found, few species accounted for most of the diet, suggesting specialized feeding, as confirmed by the low value of the Levins' standardized index. Individual feeding specialization on hermit crabs, brachyuran crabs and prosobranch gastropods was evidenced by a PCA performed on proportions of prey abundance.