Rediscovering the tortoise-crab, Cryptocnemus vincentianus Hale, 1927 (Brachyura: Leucosiidae)

The tortoise-crab Cryptocnemus vincentianus (Decapoda, Brachyura, Leucosiidae) was first described in 1927 based on one specimen, and with only one specimen recorded since, nothing is known about its biology. We document 11 recently discovered individuals of this species from the Gulf St. Vincent in South Australia. The original description was based on a single female, whilst our records comprise five females and six males. The morphology of male individuals of this species is described for the first time. Male specimens were smaller than female C. vincentianus. The habitat consisted of medium to coarse sediment in depth to 20 m. The crab was rare based on both occurrence (constancy index <10%) and abundance (<0.001% of all macrofauna recorded). Comments on the conservation status of the species are provided.