Brown Shawl Crab
The Brown Shawl Crab has an Indo-West Pacific distribution. In Australia it ranges from Shark Bay, WA, across NT and Qld to mid-coastal NSW (WA, NT, QLD, NSW).Features:
The Brown Shawl Crab is a light-brown oval shaped crab, with a wide and long, arc-shaped front edge to the carapace. It grows to a carapace width of 120 mm. It has small brown eyes.
The front of the carapace is extremely broad compared to the rear, which is quite indistinct. Two thirds of the way around its carapace edge, a blunt bump divides the front from the very short side and rear edges. The upper surface of the carapace is convex (curving outwards) and is quite smooth, without any major spines. It has large equal-sized chelae with brown fingers. Its legs often have distinct crests. The males of dark-fingered crabs have the usual complement of seven abdominal segments reduced to five by having segments three to five fused together.
The Brown Shawl Crab is a uniform light brown to reddish brown in colour, with white "lace-work" mottling on the carapace and brown spotted limbs. Underneath the carapace is cream in colour.Ecology/Way of Life:
The Brown Shawl Crab is found in intertidal regions and below to 50 metres, on rocky, coral, or mud shores. Its relation, the Poisonous Shawl Crab, Atergatis floridus, is poisonous if eaten.
The Brown Shawl Crab is a member of the dark-fingered Xanthidae family of crabs. The Xanthidae are the most diverse and numerically abundant family of crabs in coral reef habitats.Interaction with Humans/Threats:
Because of its extensive distribution range and its ability to live in a range of habitats, this species is probably under no threat from human activity.Other Comments:
Atergatis integerrimus. The word Atergatis may come from the Latin word tergum, which means the back. An "A-" in front means without. This describes the feature that members of this genus of crabs have an indistinct back edge to the carapace compared to the expansive, arc-shaped front edge.Further Reading:
Allen, G. R. & Steene, R. (1994) Indo-Pacific Coral Reef Field Guide. p.135. Tropical Reef Research, Singapore.
Davey, K. (1998) A Photographic Guide to Seashore Life of Australia. New Holland Press, p.51, Sydney.
Healy, A. & Yaldwyn, J. (1970) Australian Crustaceans in Colour. A.H. & A.W. Reed. Jones, D. & Morgan, G. (1994). A Field Guide to Crustaceans of Australian waters. p. 167, Reed.
Text, map & photographs by Keith Davey.
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