Perophora listeri Forbes, 1848

Dwarf ascidian

Description: Colonies consist of large numbers of small transparent zooids connected by basal stolons. The branchial sac, orange-brown stomach and chains of grey faecal pellets can all be seen inside the zooid when it is alive. 5mm x 4mm x 2mm.

Habitat: Found in sheltered places from lower shore to 30m growing on a variety of substrata, especially on hydroids and bryozoans, even on crabs such as Hyas araneus.

Distribution: West coasts of the British Isles south to the Mediterranean.

Similar Species: There is no other common small ascidian in the British Isles with separate zooids connected by a stolon. See also Protostyela heterobranchia - description in Millar.

Key Identification Features:

• Small separate zooids connected by stolon.
• Transparent test and body.

Distribution Map from BioMar data for Ireland - Google Earth map:  download this placemark (not got Google Earth installed?)

Distribution Map from NBN: JNCC MNCR data - Grid map National Biodiversity Network mapping facility, data for UK.