The largest sea turtle species is the leatherback sea turtle. Characterized by its distinct, leathery shell rather than a hard carapace, the leatherback can weigh up to 2,000 pounds and measure over six feet in length. This migratory species feeds primarily on jellyfish and has a unique physiological adaptation that allows it to regulate its body temperature in cold waters. Leatherbacks are found in oceans around the world and are considered vulnerable due to threats such as habitat loss, poaching, and entanglement in fishing gear. Conservation efforts are crucial to ensure the survival of this remarkable marine turtle species.