Description: This is a small nudibranch, with adults only growing to about 12mm. The body is translucent white, with scattered brown or green pigment on the back and cerata. The cerata have 2-3 rows of tubercles. The tip of each ceras is covered by a pale patch and encircled by a brown-coloured ring. The rhinophoral and oral tentacles are smooth, the tips of these tentacles are white with a sub-terminal brown band.

Habitat: This species feeds on the plumularian hydroid Kirchenpaueria similis which is like a smaller, finer version of Kirchenpaueria pinnata. The spawn is similar to Eubranchus vittatus.

Distribution: Few records exist for this species, however it has been found around the southern and western coasts of the British Isles, Lundy Island and Pagham Harbour, Sussex, north to Mulroy Bay, Co. Donegal and St Kilda, off the west coast of Scotland.

Similar Species: Capellinia fustifera is sometimes confused with Eubranchus vittatus but may be readily distinguished by the presence of tubercles on the cerata. Capellinia doriae may be a separate species but is probably only found in the Mediterranean.

Key Identification Features:

• Cerata with irregular swellings over outgrowths of digestive gland.
• Body with green patches.

Distribution Map from NBN: Capellinia fustifera at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Capellinia fustifera at iNaturalist World Species Observations database.

WoRMS: Capellinia fustifera at World Register of Marine Species. Accepted name: Capellinia fustifera (Lovén, 1846). AphiaID: 1339732.

Classification: Biota; Animalia; Mollusca; Gastropoda; Heterobranchia; Euthyneura; Ringipleura; Nudipleura; Nudibranchia; Cladobranchia; Fionoidea; Eubranchidae; Capellinia