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: Styela clava at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Styela clava at iNaturalist World Species Observations database.

WoRMS: Styela clava at World Register of Marine Species. Accepted name: Styela clava Herdman, 1881. AphiaID: 103929.

Classification: Biota; Animalia; Chordata; Tunicata; Ascidiacea; Stolidobranchia; Styelidae; Styela