Description: This spherical sponge is typically pale to bright yellow in colour but can also be orange. The surface is tuberculate (warty) and often 'buds' are present, found on short stalks on top of these tubercles. There is one, large compound oscule opposite to the point of attachment. Overall the appearance is like a small orange.

Habitat: A common species in the infralittoral zone, usually on horizontal or gently sloping rocky surfaces in clean water, but can tolerate silt.

Distribution: A common species on western and southern coasts of the British Isles.

Similar Species: This species may be confused with Suberites carnosus however the latter species has a smooth velvety surface. Tetilla cranium and Tetilla zetlandica are the same shape and have a rough surface, but T. zetlandica is bright white and T. cranium has distinctive 'S' shaped microscleres.

Key Identification Features:

• Spherical shape.
• Tuberculate surface, often with stalked 'buds'.
• Large compound oscule opposite point of attachment.

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

iNaturalist: Tethya citrina at iNaturalist World Species Observations database.

WoRMS: Tethya citrina at World Register of Marine Species. Accepted name: Tethya citrina Sarà & Melone, 1965. AphiaID: 134312.

Classification: Biota; Animalia; Porifera; Demospongiae; Heteroscleromorpha; Tethyida; Tethyidae; Tethya