New Zealand Screwshell

Marine species not currently found in South Australia.

The New Zealand Screwshell is a marine mollusc which competes for food and habitat with native species. Densely blankets the sea floor with live & dead shells. Can compete with scallops and commercially farmed shellfish for food.

Declared noxious under the Fisheries Management Act 2007. Noxious species are a severe threat to the natural environment and industries. They cannot be held or traded in South Australia without specific authorisation and must not be returned to the water if caught.

What to look for:

• Smooth conical shell
• Generally brown, fading to purple/white with age
• Broader tapering shell with up to 18 whorls
• Up to 9 cm long, usually about 6 cm

More information on identification can be found at Marine Pests.