Only one species occurs in Australian waters – Homoioplax haswelli.

[2] The various genera of the Panopeidae are morphologically similar, partly as a result of many instances of convergent evolution to similar habitats and food preferences.

[3] Crabs of the family Panopeidae are all free-living (not commensal or parasitic),[2] and typically live in soft-bottomed parts of the ocean,[3] lending them the common name "mud crabs" (a name also shared by other organisms).

They burrow into the sediment and feed on a variety of marine invertebrates.

[3] The World Register of Marine Species lists these subfamilies and genera:[1] Eucratopsinae Stimpson, 1871 Panopeinae Ortmann, 1893