Description: This small worm builds thin chalky tubes on hard substrata which join together to form shallow incrustations on hard substrata. The body of the worm is a greyish-pink and is translucent. When the worms have their radioles (tentacles) extended the colony has a furry or fluffy appearance. Each crown of radioles is made up of 8 colourless, white or pinkish tentacles. They have a distinctive yellow, cup-shaped operculum on two of these tentacles.

Habitat: Encrusts a variety of hard substrata ranging from bedrock and boulders to other bryozoans, and sometimes even found on kelp.

Distribution: Recorded from all coasts of Britain and Ireland. Few records from the east coast of Scotland.

Similar Species: Resembles Salmacina dysteri but F. implexa it tends to grow in shallow incrustations and not form the dense mesh like S. dysteri, and has opercula.

Key Identification Features:

• Colony forms shallow incrustations on hard substrata.
• Crown of 8 radioles, colourless or white to pink in colour.
• Two distinctive yellow, cup-shaped opercula.

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

iNaturalist: Filograna implexa at iNaturalist World Species Observations database.

GBIF data for Filograna implexa

WoRMS: Filograna implexa at World Register of Marine Species. Accepted name: Filograna implexa Berkeley, 1835. AphiaID: 130989.

Classification: Biota; Animalia; Annelida; Polychaeta; Sedentaria; Canalipalpata; Sabellida; Serpulidae; Filograninae; Filograna