Being the largest species of sea turtle, it can reach up to 2 metres in length, weighting more than 500kg. The shell is covered by a thick, rigid and leathery skin with 5 keels or dorsal ridges (7, when considering those present on each flank). The colour is bluish-black on the back and lighter ventrally, punctuated with irregular light-coloured spots, particularly on the ventral surface. They are solitary animals that approach the coast to reproduce and feed on a number of organisms, such as: algae, jellyfish, echinoderms, molluscs, fish and crustaceans. Although this species occurs in our waters, it does not reproduce on the Portuguese coast. Present in all oceans, its distribution comprises cold, temperate, subtropical and tropical waters. It is the second most stranded species of sea turtle in mainland Portugal.