Asian paddle crab


The Asian paddle crab, sometimes called Lady Crab, can vary in colour from red/purple/orange to pale green and off-white. It has six distinct spines either side of the eyes with the shell width reaching 12cm.

It is an aggressive crab that can outcompete with native species for food and habitat. It is also known to carry the White Spot Syndrome Virus that can impact native and farmed prawns, crabs and lobsters.


Asian paddle crab / Charybdis japonica

Key features:
  • Varied colour from red/purple/orange to pale green and off white
  • 6 spines either side of eyes
  • Shell width up to 12cm
  • Swimming paddles on last set of legs
Known locations:
  • Single live male found in SA
  • Not known to occur in NSW
  • Estuarine and marine habitats
  • Subtidal to 10-15m depth
  • Is host/carrier of the White Spot Syndrome Virus which can infect native and farmed prawns, crabs and lobsters

Asian paddle crab

Similar native species

These native species may be confused with this marine pest.

Blue swimmer crab / Portunus pelagicus

Key features:
  • No spines either side of eyes
  • Dark brown/bluish/purple colour
  • Shell width up to 21cm
  • Sheltered sand and seagrass habitat
  • Intertidal and subtidal up to 60-70m depth

Mud crab / Scylla serrata

Key features:
  • 9 spines either side of head
  • Dark brown to mottled green
  • Large robust claws Shell up to 25cm wide
  • Soft muddy bottoms in sheltered areas such as mangroves

Coral crab / Charybdis feriata

Key features:
  • 6 broad teeth on either side of eyes
  • 8 rounded teeth between the eyes (Note: in C. japonica the teeth are sharp)
  • Pattern of orange/brown and white longitudinal strips on carapace
  • Legs and claws orange/brown with scattered white spots
  • Shell width up to 20 cm
  • Swimming paddles on last set of legs
  • Sandy and muddy sustrates from shore to 30 m depth

Blue swimmer crab

Mud crab

Coral crab

What is NSW DPI doing?

On the 1st July the NSW Government implemented the new Biosecurity Act 2015 (the Act). Under Schedule 2 of this Act the Asian paddle crab is declared as prohibited matter in NSW. This means it is illegal to possess, buy, sell or move this pest in NSW. Heavy penalties apply for non-compliance. In addition, NSW DPI has the power to seize and require the destruction of this pest.

People are expected to have a basic level of knowledge about the biosecurity risks they might encounter in their normal work and recreational activities. All community members have a general biosecurity duty to consider how actions, or in some cases lack of action could have a negative impact on another person, business enterprise, animal or the environment. We must then take all reasonable and practical measures to prevent or minimise the potential impact.

How can you help?

Learn to recognise, and be aware of, the Asian paddle crab so that you can report any suspected new sighting.

Report any suspected new sightings on the 24 hour recorded hotline: 02 4916 3877 or email

If you see this pest in NSW, please report it immediately

  • Note the exact location
  • If possible take a photo and/or collect a sample
  • Freeze sample in a plastic bag
  • Report your sighting