General Description

Body purple. Claws purple with white tips in adults, orange-red in juveniles. Carapace oval shape, curved at the sides and wider than long. Claws curled or twisted at the tips. Up to 3 cm wide (carapace).

Biology

Semaphore Crabs wave their twisted claws in the air to signal to other crabs from the opening of their burrow. They live in vertical burrows with a terminal chamber. When the burrow is covered by water, they plug the end of the burrow with mud. They are communal, often forming groups, but will fiercely defend their own burrows. The claws of adult males are bigger than those of the females.

Distribution

Eastern Australia.

Habitat

Mudflats at high tide level in sheltered waters.

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