Mediterranean white shark-cetaceans interactions through time: a comparison between Pliocene and Recent data

Evidence of white shark-cetacean trophic interactions from Pliocene and Recent central Mediterranean Sea is examined. The analysis of Recent data (stomach content reports, eyewitnesses' depositions about predation on living cetaceans and scavenging signs on the carcasses) shows that cetaceans represent a significant component of the diet of Carcharodon carcharias. Fossil evidence (cetacean bones marked by white shark bites and white shark teeth in close relation with skeletal remains of cetaceans) suggests sharks-cetaceans trophic interaction in the Pliocene too. A comparison between Recent and fossil data suggests that both Mysticeti and Odontoceti were equally represented in the Pliocene Carcharodon carcharias diet. On the contrary in the Recent the white shark interaction is principally directed to little-sized toothed whales and only rarely to mysticete baleen whales. this change could be due to both the general reduction of hte living white shark body size and the diminished diversity of the cetacean assemblage.