Feeding Ecology and Trophic Overlap of Sympatric Rajidae Species in the Eastern Ionian Sea (Central Mediterranean)

The feeding ecology of sympatric elasmobranchs provides key insights into trophic interactions and species coexistence within demersal ecosystems. The current study examined the diet composition and trophic relationships of three skate species (Raja asterias, Raja clavata, and Raja miraletus) in the eastern Ionian Sea (central Mediterranean). Stomach content analysis was combined with quantitative dietary indices and multivariate statistical approaches, including NMDS, PERMANOVA, SIMPER, and Schoener’s overlap index. All skate species primarily consumed benthic crustaceans and demersal teleost fishes, although differences in prey contribution were detected among species. Raja clavata exhibited higher prey diversity, whereas R. asterias and R. miraletus showed stronger reliance on decapod crustaceans. Multivariate analyses revealed significant interspecific differences in diet composition with generally low-to-moderate trophic overlap among species. These findings suggest that sympatric Rajidae species exploit similar prey resources while maintaining partial trophic partitioning, possibly reducing direct niche overlap and facilitating ecological coexistence. This study contributes to the understanding of trophic structuring in Mediterranean skate assemblages and supports ecosystem-based approaches to demersal fisheries management.