Harris' mud crab (Rhithropanopeus harrisii) competes with native species and can spread crustacean diseases. It can damage the catch in fishing nets and clog water intake pipes.
What to look for
- greenish brown to olive green
- white-tipped claws, unequal size
- hairy abdomen
- 4 spines on each side of body
- slight notch between the eyes
- eyes not at the widest point of the body
- body about 1–2cm wide
- often found in dense groups.
Where to look
Look on or around:
- fishing nets
- rocks and stones
- vegetation and oysters
- water intake pipes.
Likely habitats include:
- salt, brackish or fresh water
- shallow waters.
Similar native species
These native species look similar to Harris' mud crab. It does not need to be reported.
River swimming crab (Varuna litterata)
- red-brown body
- body up to 5.5cm wide
- claws are the same size
- 3 spines on each side of body
- flattened legs
- legs covered with long hair on inside edge of last 2 segments.
- can live in fresh or salt water
- prefers sandy areas with high tidal flushing.
See something unusual? Report it. Even if you’re not sure.
If you see something you think is a pest:
- note the exact location
- take a photo (use something for size reference, like a coin or note)
- contact your state or territory authority.
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.
The map shows known pests and pests to look for around Australia.