Carpet Sea Squirt

Didemnum vexillum

Identifying features

  • Pale orange to off white
  • Firm texture, like leather
  • Forms large mats, sometimes with hanging outgrowths
  • Overgrows other plants and animals
  • Found at Largs in the Firth of Clyde, mainland Scotland


  • Fouls harbour, marina and aquaculture structures
  • Foul boat hulls
  • Fouls mussel lines and oyster beds

Carpet sea squirt growing over seaweed. Images: C Beveridge (SAMS).

Carpet sea squirt underwater, with siphons open. Image: US Geological Survey/photo by Dann Blackwood (USGS) [Public domain], via Wikimedia Common.