Smooth-handed Crab, Pilumnopeus serratifrons
This is a small, globe-shaped crab with a hairy covering on its legs while the carapace has few hairs.
The male crab has very large equal-sized chelae. The carapace has three broad spikes, called teeth behind the eye. The walking legs and chelae do not have any spines. It has very short eyestalks.
This crab is purple-brown above with a mottled pattern It has pale brown to yellow chelae. The fingers of the chelae are distinctly coloured black, tipped with pale brown..
The Smooth-handed Crab ranges from Queensland, around the southern shores to the Swan River in Western Australia.
It is common among seagrasses on tidal flats, in estuaries and among rock and wood structures.
Camouflage, or protective behaviour
When disturbed, the Smooth-handed Crab will not attempt to try and scuttle away but instead folds its legs tightly underneath its body and pretends that it is a pebble.
Male Smooth-handed Crabs, Pilumnopeus serratifrons, can be parasitised by a species of shelless Barnacle Saccula sp. which lives part of its life cycle under the male's abdominal plate. The parasitic barnacle feeds on the living crab's tissue.
Click here for a detailed description of this parasitism.
Barnes, R. D. (1968) Invertebrate Zoology. p. 467, W.B. Saunders Company, Philadelphia.
Bennett, I. (1987) W.J. Dakin's classic study: Australian Seashores. p.391, Angus & Robertson, Sydney.
Davey, K. (1998) A Photographic Guide to Seashore Life of Australia. p.52, New Holland, Sydney.
Jones, D. & Morgan, G. (1994) A Field Guide to Crustaceans of Australian Waters. p.182, Reed, Chatswood.