About
This crab named after their behaviour of waving their twisted claws in the air to communicate with other crabs. The only species in this genus and family they are identified by their shape being wide across the carapace and narrow in length, the carapace is a mottled dark colour whilst their claws vary with age and sex. The juvenile crabs having a greenish claw that changes to orange and pink and finally mature males with purple claws.The crabs emerge from their burrows during low tide to feed detritus in the sediment of the mud flats and river banks where they live often swarming in numbers over the mud only to disappear when they sense nearby movement or disturbances.