Oval Spider Crab

Halicarcinus ovatus

Systematics: Brachyura Family Hymenosomatidae

Distinguishing Characters:
These crabs occur in a variety of dramatic colours, usually in symmetrical patterns, including red-black, red-white or brown-white. They are little crabs, rarely more than 13 mm wide. The carapace is curiously flat, almost concave, with areas marked with fine grooves and strongly defined at the edge. The legs are very fine and longer than the carapace. The chelipeds of the male are enlarged.

Habitat and Distrbution:
The oval spider crab is common in seagrass beds and under rocks at lower levels along the entire coast of southern Australia.

General Biology:
These tiny spider-like crabs are very common in marine environments. They are presumed to be scavengers but might be micropredators. They feature in the diet of several species of bottom feeding fishes.