Description: Usually grows as small, thin patches (up to 40 x 5 mm)with a pale yellow to bright sulphur yellow colour and a conulose surface. It is soft and compressible. There are no spicules. There are one to several oscules, which are often mounted at the ends of oscular chimneys, 1-3 mm wide.

Habitat: On the low shore under boulders and in the shallow sublittoral in caves or beneath overhangs. Often found with Aplysilla rosea.

Distribution: Found from the littoral to 320 m depth. Found all around Britain and Ireland but not as common on North Sea coast of Britain.

Similar Species: Unlikely to be confused with any other species.

Key Identification Features:

• Bright yellow colour
• Conulose surface

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

iNaturalist: Aplysilla sulfurea at iNaturalist World Species Observations database.

WoRMS: Aplysilla sulfurea at World Register of Marine Species.