Not as big as the dinosaurs, but possibly as old, sharks first appeared 450 million years ago! More than 25 species of sharks inhabit the waters of the Channel Islands. Unlike fish, sharks lack bony skeletons, scales and air bladders. By day, blue sharks (Prionace glauca) are a common resident offshore, often visible from boats cruising the channel. By night, blue sharks move inshore to feed on anchovies and squid. (photo: Shane Anderson)