Oyster drill

Ceratostoma inornatum and Urosalpinx cinerea


Habitat: Found on the lower shore and sublittoral to a depth of about 12 m, feeding especially on oysters.


Description: Ceratostoma inornatum has a narrow and elongated physiology. It is around one inch (2.54cm) long. The radula is the band of teeth that acts as a "drill" to penetrate the shells of oysters.


Origin and Distribution: The Asian oyster drill is native to Japan and the Republic of Korea. The American oyster drill is native to the east coast of the USA. The Asian oyster drill is now known from France and has also spread to North America. The American oyster drill is now present on the south coast of England.


Impacts: Urosalpinx cinerea and Ceratostoma inornatum predate on native and commercial oyster beds. They feed by boring through oyster shells. These species can cause a 25% reduction in oyster farm production.


How might it get here? Contamination of aquaculture seed stock and equipment.



Prevent Spread:

  • Promotion of native species and biodiversity.
  • Ensure compliance with the ICES Code of Practice on the Introductions and Transfers of Marine Organisms 2005.
  • Inspect – remove – dispose – Report.
  • Audit your activities.
  • Ensure biofouling control on aquaculture equipment
  • Prevent fouling of vessels and mooring lines.
  • Always remove fouling prior to long distance journeys
  • Remove unused equipment and stock


Invasive Species Ireland

Invasive Species Ireland