Leathery sea squirt

Styela clava


Photo credit: ©Chris Wood, Marine Conservation Society
Leathery sea squirt - Styela clava
  • It is found on hard surfaces in shallow water, and is often seen in warm water docks and harbour installations.

  • It has a long club-shaped body, which tapers to a slider, tough stalk.
  • It can reach 12cm in length, and the stalk can be up to a third of the total length.
  • Its skin can be leathery; folds and swellings are present.
  • The siphons are close tighter at the top of the body. 
  • Download N.I.E.A. ID guide

Origin and Worldwide Distribution:
  • It is native to the north western Pacific, being found in Japan, Korea and Siberia.
  • It is now found in France, the Netherlands, Denmark and Ireland.

Potential or Known Impacts:
  • It may become the dominant species, if high densities occur, therefore causing a decrease of native invertebrates.
  • In oyster and mussel beds, it can compete for food and space. It may foul these commercial beds, along with buoys, moorings and boats.

How did it get here?
  • It likely got here on the hulls of boats. It can also fouls oyster beds, providing another pathway to spread along.

Is it found in Ireland or Northern Ireland?
  • It is present in Ireland and Northern Ireland.

You can help by reporting any sightings:
Methods for Prevention:
  • Report all sightings. 
  • Check, clean and dry equipment to prevent spread.

Species Related Files:

Invasive Species Ireland

Invasive Species Ireland