AQWA Facts: Western rock lobster
Scientific name: Panulirus cygnus
A crayfish’s segmented legs and hard outer covering places them in the same group of animals as insects. They also share a compound eye. This means that their vision is alike a kaleidoscope – lots of different images at once.
Crayfish east with their feet!
Crayfish have 10 pairs of ‘legs’. Some are used for walking, some for swimming, some for eating and some for tasting!
They smell with their small antennae and use their big spikey antennae for feeling around, defending themselves and to ‘talk’.
Spiny body armour
Rock lobsters are unique as they don’t have the large claws of traditional lobsters. They belong to the ‘spiny lobster’ family and have hundreds of sharp thorny pines covering their body. For further protection they have two horns on their head; long spikey antennae that are swung like clubs; and a hard outer covering, called a carapace, that acts like a suit of armour.
When crayfish get too big for their hard outer shell, they break free and grow a new one. This is called moulting. If they have lost a leg or broken an antennae it regrows while they moult.
Rock lobsters can live for over 20 years and it is thought that they never stop growing!
The long march
Crayfish have a migratory phase to their life cycle. In late spring young adults, known as ‘whites’ due to their pale carapace, migrate on mass to into deeper water. Trekking only at night they march in a set formation hundreds of kilometres west into water up to 100m deep.
Did you know?
A crayfish’s teeth aren’t in its mouth – they are in its stomach! Called a gastric mill it is made up of 3 molar teeth.
Where at AQWA?
Search the caves and crevices of our Perth Coast exhibit area for these nocturnal wonders.
Size: <5 kg
Diet: Coralline algae, detritus, molluscs, crustaceans
Main predator: Fish, octopus, sea lions
Habitat: Seagrass, reef
Found: WA only