Aquarium caulerpa

Body contents

Aquarium caulerpa (Caulerpa taxifolia) can overgrow native species and degrade fish habitats. It can also tangle in nets and anchors.

This pest can live for 2 weeks out of water. It can reproduce from fragments as small as 2mm.

What to look for


  • light green
  • flattened fronds
  • pinnules curve upwards and grow directly opposite each other
  • grows up to 15cm long (can be over 60cm in deep water).
Aquarium caulerpa
Aquarium caulerpa

Where to look

Look in or around:

  • mud
  • rocks
  • sand
  • seagrass beds.

Likely habitats include:

  • hard and soft surfaces
  • shallow waters.

Native to northern Australia, from Port Denison, Western Australia to Southport, Queensland. Can be a pest in some southern locations. Established in some parts of New South Wales and South Australia.

Similar native species

These native species look similar to Aquarium caulerpa. They do not need to be reported.

Caulerpa scalpelliformis


  • pinnules attached alternately, not opposite
  • fronds up to 20cm long.


  • hard and soft surfaces
  • seagrass beds
  • shallow waters, up to 36m deep.

Known to occur from Jervis Bay, New South Wales to Whitford Beach, Western Australia, and Tasmania.

Caulerpa cupressoides


  • short pinnules
  • pinnules attached opposite, widely spaced along midrib.


  • hard and soft surfaces
  • coastal areas.

Known to occur from Abrolhos, Western Australia, around northern Australia to Lord Howe island, New South Wales.

Caulerpa distichophylla


  • short pinnules
  • pinnules attached opposite, closely spaced along midrib.


  • hard and soft surfaces
  • shallow waters, up to 7m deep.

Known to occur in Western Australia, from Dongara sound to King George Sound.


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, like a coin or note)
  • contact your state or territory authority.



Stop the spread of marine pests

Start with these simple steps:

  • Check anchors and other equipment for tangled algae.
  • 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.

Aquarium caulerpa

Aquarium caulerpa (Caulerpa taxifolia)

In Australia

Features: Light green. Flattened fronds. Pinnules curve upwards and grow directly opposite each other.
Habitat: Estuaries, coastal lagoons, bays.
Affects: Native habitats and fish, tangles nets and anchors.
Movement: Vessels, fisheries and aquaculture, ornamental (aquarium) trade.