Ascarosepion plangonAscarosepion plangon, the mourning cuttlefish, is a species of cuttlefish found along the east coast of Australia.ClassificationAscarosepion plangon was first scientifically described under the name Sepia plangon by J. E. Gray in 1849.DistributionMourning cuttlefish are found along the eastern coast of Australia in the states of Queensland, New South Wales, and Victoria, and are common in Sydney Harbour, especially in Chowder Bay. It is one of only three cuttlefish species that live in Sydney, the others being the giant cuttlefish and the reaper cuttlefish.