Styela clava Herdman, 1881

Description: This solitary sea squirt is unique amongst the British ascidians in having a basal stalk. The test is covered with detritus and algae, giving a dirty brown appearance. The siphons are at one end of the elongate body. They are marked with purple and cream longitudinal stripes. Grows to 120mm long x 15mm wide.

Habitat: In sheltered areas attached to man-made surfaces, harbour walls etc.

Distribution: An introduced species in the British Isles, common in Southampton harbour, Portsmouth harbour, Milford Haven, etc.

Similar Species: Small specimens which have not grown a stalk could be confused with Pyura microcosmus.

Key Identification Features:

• Elongate test with stalk at base.
• Terminal siphons with purple longitudinal stripes.

Distribution Map from NBN: Interactive map : National Biodiversity Network mapping facility, data for UK.

WoRMS: Species record : World Register of Marine Species.