Black Finger Crab

Ozius truncatus

The Black Finger Crab, also known as the reef crab, is a crustacean endemic to Australia, particularly found in the southern and southwestern regions including Western Australia, South Australia, Victoria, and southern New South Wales. It is often confused with its close relative, Ozius deplanatus, found in eastern Australia and New Zealand. The key distinguishing feature of Ozius truncatus is the groove that interrupts its epibranchial ridge, whereas Ozius deplanatus has a slightly wider carapace. The carapace of the Black Finger Crab is oval-shaped, measuring up to nearly 60 mm across. This species inhabits the intertidal zone, often residing beneath boulders. It thrives in shallow waters, typically at depths ranging from 0 to 5 meters. The Black Finger Crab is benthic and can be encountered in subtropical regions. Its diet consists mainly of marine snails, limpets, and other small invertebrates, which it actively hunts in its rocky habitat. The reproductive behavior of the Black Finger Crab involves a precopulatory courtship ritual, utilizing olfactory and tactile cues. Mating usually involves indirect sperm transfer, a common trait among members of the order Decapoda. As of now, the conservation status of the Black Finger Crab has not been evaluated by the IUCN.