A NSW Government website

Slipper limpet


The slipper limpet has a smooth oval shaped shell up to 5cm long. It tolerates a range of environments and habitats, and can be found from muddy to rocky intertidal areas of estuaries and coastal bays.

The slipper limpets create dense stacks, sitting on top of one another competing with native bivalve species for space and food. It has high survival and settlement rates that can impact native bivalve settlement and oyster aquaculture industries.


Slipper limpet Crepidula fornicata

Slipper limpetKey features:

  • Smooth oval shaped shell up to 5cm long
  • Irregular growth lines
  • Internal shelf extending half shell’s length
  • White, yellow or pink with red/brown streaks
  • Commonly found in stacks

Known locations:

  • Not recorded in Australia


  • Intertidal areas of estuaries and coastal bays
  • Attached to other shells or hard surfaces in muddy/sandy/gravel/rocky areas

Slipper limpetImpacts:

  • Can compete with natives for food and space
  • Can impact commercial oyster cultivation

Similar native species

These native species may be confused with this marine pest.

Northern slipper limpet / Spiny slipper limpet Crepidula aculeata

Key features:Shell commonly 1-3cm (up to 4cm), has spines and bumps, white and brown colour

Habitat:Intertidal to subtidal, exposed rocky shores

Northern slipper limpetNorthern slipper limpet

Southern slipper limpet / Crepidula immersa

Key features:

  • Flat/thin shell up to 5cm long with internal shelf
  • White to fawn/brown colour


  • Subtidal up to 350m depth

Southern slipper limpetSouther slipper limpet

Limpet / Notoacmea mayi

Key features:

  • Smooth shell, no internal shelf


  • Exposed reef, high intertidal zone


What is NSW DPI doing?

On the 1st July the NSW Government implemented a new Biosecurity Act 2015 (the Act). Under Schedule 2 of this Act the Slipper Limpet 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 the 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 slipper limpet so that you can report any suspected sighting  immediately.

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