Common name: Aussie Crab, Crazy Crab, Calico Crab
variabilis: varied, different
Distribution: Northern Australia, from Exmouth Gulf to North Queensland.
Habitat: Occuring intertidally and higher up, above tide levels, up to 100m or so from the beach. These crabs are most common near mangroves but they also occur on sand and rocky beaches.
Ecology: Found far away from the beach, 100 M or more. Nocturnal, supratidal, terrestrial (desert or dune, forest, scrub forest), coastal
carapace and the clawed legs lack distinct spines. The eyestalks are
compressed from side to side. The stalks (peduncles) of the antennules
are very long but the feelers (flagella) are short and compressed from
side to side. These crabs reach a carapace length of 40 mm.
Cream or pale brown, with some variable darker brown markings, on the shield and on the legs.
Males and females differ only in the position of the gonopores.
Large numbers of C. variabilis can be found behind mangroves, sheltering from the heat of the day under rocks or logs. They are very active nocturnal scavengers. The crabs are especially attracted to decaying material, such as dead fish on the beach, and even to the household garbage and pet's feeding bowls. They are also sold commercially as household pets, usually under the name of 'crazy crabs'.
Exclusive to Australia, the '''C. variabilis''' is often named the
'''Crazy Crab''', after the name of the first company to harvests and
market them. They are similar in appearance to Coenobita compressus in
their compressed peduncles (eye stalks) and share other similarities
including choice of seashells.
Both C. variabilis and C. compressus have an abbreviated development (shortened aquatic stage)
References: Jones, S. and
Morgan, G.J. (1994)
"A Field Guide to Crustaceans of Australian Waters".
Western Australian Museum. Chatswood, N.S.W. (Australia) : Reed Books, 1994.
ISBN 0 7301 0403 6