Description: This worm is up to 120 mm long but lives in a self-constructed tube that is buried in soft sediments and retracts quickly when disturbed, so all that is normally visible when in situ is a crown of long radioles (up to 30 per side, although more usually around 50 in total), each with a large eye towards the end. The collar is distinct and fused to the mid-dorsal groove. The tube itself only protrudes a maximum of 2-3 cm above the surface of the sediment, and is untidy in appearance, covered with pieces of sand and gravel. Uncini on the thorax and abdomen as S-shaped, and the companion chaetae have leaf-shaped blades. The radioles and body can be yellow, brown or red-purple and are usually spotted.

Habitat: Lives in a tube buried in coarse sand and muddy gravel. Occasionally found amongst Zostera marina.

Distribution: Found around most coasts of Britain and Ireland aside from east coast of Britain.

Similar Species: There are other burrowing tube worms that could potentially be confused with this species, inspection of the collar and the presence of eyes on the radioles helps to distinguish.

Key Identification Features:

• Tubeworm with up to 30 radioles on each side of crown.
• Large, bulbous eye towards the end of each radiole.
• Uncini on thorax and abdomen S-shaped; companion chaetae with leaf-shaped blades.
• Collar distinct and fused to mid-dorsal groove.

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

iNaturalist: Acromegalomma vesiculosum at iNaturalist World Species Observations database.

GBIF data for Acromegalomma vesiculosum

WoRMS: Acromegalomma vesiculosum at World Register of Marine Species. Accepted name: Acromegalomma vesiculosum (Montagu, 1813). AphiaID: 994123.

Classification: Biota; Animalia; Annelida; Polychaeta; Sedentaria; Canalipalpata; Sabellida; Sabellidae; Sabellinae; Acromegalomma