Sepia apama, also known as the giant cuttlefish and Australian giant cuttlefish, is the world's largest cuttlefish species, growing to 50 cm in mantle length and over 10.5 kg (23 lb) in weight. Using cells known as chromatophores, the cuttlefish can put on spectacular displays, changing color in an instant.S. apama is native to the southern coast of Australia, from Brisbane in Queensland to Shark Bay in Western Australia.