Creeping sea squirt (Perophora japonica)

Distribution data supplied by the Ocean Biodiversity Information System (OBIS). To interrogate UK data visit the NBN Atlas.Map Help



Colonies of small, translucent zooids (approximately 4 mm long) budded from stolons and generally rather closely packed. Young parts of colony are yellow or greenish-yellow. Stolons may bear angular, often star-shaped, terminal buds, which are bright yellow.

Recorded distribution in Britain and Ireland

Recorded in Queen Anne's Battery Marina, Plymouth Sound; the Fleet, Dorset approximately 130 km from Plymouth, and in Guernsey.

Global distribution

Also recorded from the English Channel coast of France. Originally described in Japan, and reported from Korea.


At Plymouth, it grows on fucoid algae, hydroids and artificial settlement panels on the underside of a floating pontoon. In France, it is reported growing on Sargassum muticum, fucoid algae, Laminaria spp., sponges, solitary ascidians, oysters, and directly on floating pontoons.

Depth range


Identifying features

No text entered

Additional information

First recorded in Queen Annes Battery Marina, Plymouth Sound (first noted in 1999; see Nishikawa et al., 2000). Baldock & Bishop (2001) reported Perophora japonica in the Fleet, Dorset approximately 130 km from Plymouth. It was recorded in Guernsey in 2003 (Richard Lord pers comm.).

Listed by

- none -


  1. Baldock, B. & Bishop, J.D.D., 2001. Occurrence of the non-native ascidian Perophora japonica in the Fleet, southern England. Journal of the Marine Biological Association of the United Kingdom, 81, 1067.

  2. Howson, C.M. & Picton, B.E., 1997. The species directory of the marine fauna and flora of the British Isles and surrounding seas. Belfast: Ulster Museum. [Ulster Museum publication, no. 276.]

  3. Monniot, C. & Monniot, F, 1985. Apparition de l'ascidie Perophora japonica sur les côtes et dans les ports de la Manche. Compte Rendu de la Société de Biogéographie, 61, 111-116.

  4. Nishikawa, T. Bishop, J.D.D. & Sommerfeldt, A.D., 2000. Occurrence of the alien ascidian Perophora japonica at Plymouth. Journal of the Marine Biological Association of the United Kingdom, 80, 955-956.


  1. Centre for Environmental Data and Recording, 2018. Ulster Museum Marine Surveys of Northern Ireland Coastal Waters. Occurrence dataset accessed via on 2018-09-25.

  2. Fenwick, 2018. Aphotomarine. Occurrence dataset Accessed via on 2018-10-01

  3. NBN (National Biodiversity Network) Atlas. Available from:

  4. OBIS (Ocean Biodiversity Information System),  2024. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. Accessed: 2024-05-18


This review can be cited as:

Bishop, J. 2005. Perophora japonica Creeping sea squirt. In Tyler-Walters H. and Hiscock K. Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 18-05-2024]. Available from:

Last Updated: 16/08/2005