Advancing the understanding of the trophic ecology of Scyliorhinus canicula in the Mediterranean Sea: Insights from a Tyrrhenian case study and a review of current knowledge

Sharks are cartilaginous fishes that serve as both meso- and top predators in marine ecosystems. Globally, they are targeted by commercial and recreational fisheries and represent a significant portion of fishery bycatch. Among mesopredatory sharks, the small-spotted catshark (Scyliorhinus canicula) is one of the most common and widely distributed species in the Mediterranean Sea. This study investigates the diet and trophic position of S. canicula from the Tyrrhenian Sea using an integrated approach by combining stomach content analysis (SCA) and stable isotope analysis (SIA). Bayesian mixing models were applied to isotope data and suggested an ontogenetic dietary shift in the species. Additionally, we analyzed Mediterranean landings data of S. canicula, finding a consistent increase in catches up to 2019. A literature review of previous SCA studies across the Mediterranean confirmed that S. canicula is a generalist mesopredator, feeding primarily on crustaceans and teleosts—the latter becoming increasingly dominant from the Balearic to the Aegean Sea. Overall, these findings confirm the important mesopredatory role of S. canicula in Mediterranean benthic food webs and underscore the need for further investigation into the consequences of mesopredator release on the ecosystems, particularly in the context of increasing anthropogenic pressures.