Distomus variolosus Gaertner in Pallas, 1774

Description: A smooth rounded red sea squirt found in densely aggregated colonies. The small individuals have a common basal test, and increase in number by budding. The siphons have a six lobed appearance on partial contraction, which is distinctive. 5-8mm in diameter.

Habitat: Characteristic of the infralittoral, occurring on rock, kelp holdfasts and algae.

Distribution: Apparently a southern species in the British Isles, quite common on the south coast of England as far east as Dorset, and occurring on the west coast of Ireland.

Similar Species: Easily and frequently mistaken for Dendrodoa grossularia, leading to confusion over distribution.

Key Identification Features:

• Dense aggregations of small shiny red individuals.
• 6-lobed appearance of siphons.
• Internal anatomy, with numerous small gonads scattered in body wall.

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.