Semaphore is a way of signalling using your hands or flags. These crabs are called Semaphore Crabs because they can often be seen standing outside burrows signalling with their raised claws.
Do some research or talk to someone to find out some of the signals used in semaphore.
Mangroves
Semaphore Crab
Semaphore Crabs are about 2.5 cm wide. They have a mottled dark purple back. The adults have purple claws and the juveniles have orange claws. These crabs have long stalked eyes.
Common name: Semaphore Crab
Scientific name: Heloecius cordiformis
This Semaphore Crab is about to go into its burrow.
Semaphore Crabs live on the east coast of Australia. They are found on sandy flats and in estuaries, beaches and intertidal mangroves.
Semaphore Crabs eat small particles of dead plants and animals. They also eat algae and micro-organisms.
Semaphore Crabs will scoop up sand and mud with their front claws. They sift through the sand for food, dropping unwanted sand and mud.
Birds and fish eat Semaphore Crabs.
Copyright © Australian Museum, 2003
