Keep an eye out for aquatic pests this summer

29 November 2019

An Asian paddle crab
Asian Paddle Crab 

Fishers and recreational water users are being asked to keep watch and report any suspicious aquatic pests over the summer months.

Aquatic pests are a threat to our unique freshwater and marine environments, as they have the potential to impact on biodiversity, prey on native species, destroy natural habitats and introduce exotic diseases.

Over recent months, reported sightings of the invasive Asian Paddle Crab in the Port River and off eastern Yorke Peninsula have prompted a call for water users to remain vigilant for detections of the aquatic pest.

The Asian Paddle Crab is an aggressive, non-native species that has the potential to outcompete native species, such as Blue Swimmer Crab, and act as a pathway towards introducing exotic disease into our waters.

With the recreational crabbing season well underway, fishers are being urged to report any suspected detections to Fishwatch on 1800 065 522.

What to look for:

  • six spines down each side of the shell
  • grows up to 120mm wide – smaller than a Blue Swimmer Crab
  • various colours – pale, olive green, brown, purple
  • sharp spines between its eyes
  • both genders have paddles on rear legs; if it doesn’t have paddles on its rear legs it’s not an Asian Paddle Crab

It is important to confirm suspected Asian Paddle Crabs. If you think you have caught one, immediately take a photo, retain in a bucket and call Fishwatch. PIRSA staff can confirm identification, so that native crabs can be safely returned to the water.

Report any suspected sightings of Asian Paddle Crab or other aquatic pest species to Fishwatch or email

For more information visit

Asian Paddle Crab fact sheet