About Ozius truncatus H.Milne Edwards, 1834
Ozius truncatus, commonly called the reef crab or black finger crab, is a crustacean in the family Oziidae that is endemic to Australia. It is distributed across southern and south-western Australia, including Western Australia, South Australia, Victoria and southern New South Wales. A similar species, Ozius deplanatus, is found in eastern Australia and New Zealand, and was historically classified as Ozius truncatus. In Australia, the distributions of Ozius truncatus and Ozius deplanatus overlap. The two species can be distinguished by physical traits: in Ozius truncatus, the epibranchial ridge is broken by a groove, while the carapace of Ozius deplanatus is slightly wider than that of Ozius truncatus. The carapace of Ozius truncatus is oval-shaped, reaching nearly 60 millimeters across. It is around 1.4 to 1.5 times as long as it is wide. Ozius truncatus inhabits the intertidal zone, where it feeds on marine snails, limpets, and other small invertebrates.
