Description: Colonies of this distinctive bryozoan form erect branching structures attached to hard substrate via an encrusting base. Branches are irregular and thickly calcified. The colony can reach 5-10 cm in height. The colour is usually a distinctive bright orange, but may range to pale pink in some instances. Individual zooids range from rectangular to hexagonal in shape with a semicircular orifice, and are separated by deep grooves.

Habitat: Usually growing attached to bedrock or boulders, down to around 130 m (rare records exist from 500 m).

Distribution: Found all around Britain and Ireland but is a more northern species so most records are from Northern Ireland and Scotland.

Similar Species: Could be confused with Omalosecosa ramulosa but it is usually smaller and more pale. Could also be confused with Palmiskenea skenei but it has flatter branches and is usually paler in colour.

Key Identification Features:

• Usually a bright orange colour.
• Erect branching bryozoan 5-10 cm in height.
• Irregular, thickly calcified branches.

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

iNaturalist: Porella compressa at iNaturalist World Species Observations database.

GBIF data for Porella compressa

WoRMS: Porella compressa at World Register of Marine Species. Accepted name: Porella compressa (J. Sowerby, 1805). AphiaID: 111124.

Classification: Biota; Animalia; Bryozoa; Gymnolaemata; Cheilostomatida; Flustrina; Lepralielloidea; Bryocryptellidae; Porella