The Red Rock Lobster, also known as the Southern Rock Lobster or the Spiny Rock Lobster, is one of the world's rarest and commercially most sought after crustaceans. They live in and around the South Australian reefs at depths ranging from 5 to 275 meters (16 to 900 feet). They usually have a dark red or orange colour with yellow abdomens and can weigh up to about 5 kg.! They are usually found crawling on the bottom or swimming backwards by flexing their tail. Their antenna are sensitive to water vibrations and as soon as you approach them they will withdraw into their den.