Asian shore crab

Image of Asian shore crab (Hemigrapsus sanguineus) shown against a ruler.

Asian shore crab (Hemigrapsus sanguineus)

In Australia

Features: Three spines feature along the outside of the shell behind each eye. Banding pattern on walking legs. Red spots on claws. Squarish shell up to 5cm wide that can be green-purple, orange-brown or red.
Habitat: Generally hard substrates in intertidal areas, under rocks, shells, debris or artificial structures.
Affects:Native species, aquaculture operations.
Movement: Vessels.

Body contents

Asian shore crab (Hemigrapsus sanguineus) competes with and preys on crabs, and shellfish, particularly juvenile mussels or oysters.

What to look for

Features:

  • squarish shell, green–purple to orange–brown to red
  • three spines along the outside of the shell behind each eye
  • banding pattern on walking legs – distinguishing feature in juveniles
  • red spots on claws
  • males have a bulbous projection (pulvinus) on the bottom finger of each claw
  • shell up to 5cm wide
  • no hairs on the legs
  • ridge below the eye is finely striated
  • Shell is a smooth undeviating line between the eyes.
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Where to look

Look in or around:

  • artificial structures
  • under debris, rocks and shells
  • mud.

Likely habitats include:

  • intertidal rocky coasts
  • shallow water; if population is high and competition for space exists.

Established in Victoria . Asian shore crabs were detected in Port Phillip Bay in 2020.

Similar native species

These native species look similar to Asian shore crab. They do not need to be reported.

Ilyograpsus paludicola

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Features:

  • yellow shell with mottled red, brown and purple markings
  • no spines to sides of eyes
  • smooth rounded shell up to 4cm wide.

Habitat:

  • sheltered or moderately exposed rocky and boulder-covered shores.

Pseudohelice subquadrata

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Features:

  • has fewer spines along its shell
  • hair on legs

Habitat:

  • intertidal zones, estuaries, salt marshes and within mangroves

Known habitat:

  • Is widely distributed in tropical zones throughout the Indian Ocean and South Pacific Ocean

 

Report it

See something unusual? Report it. Even if you’re not sure.

If you see something you think is a pest:

  • note the exact location (screenshot your map app or enable photo geotagging on your phone)
  • take a photo (use something for size reference, for example a coin)
  • contact your state or territory authority.

Report

Stop the spread of marine pests

Start with these simple steps:

  • Inspect and clean your boat or yacht. Make sure you check hard to reach areas.
  • Treat the hull of your boat or yacht regularly.
  • Clean and dry your fishing and diving gear after every use.

How you can stop the spread of marine pests.

Your location

Check our marine pests map.

The map shows known pests and pests to look for around Australia.