Description: This is the only barnacle that can secrete its own float, but can also be found attached to very small floating objects such as seaweed, feathers, straws and other debris, including Vellela velella. The self-secreted float may be required for larger individuals to maintain their buoyancy. It can grow up to 7 cm total length, with a capitulum and very short peduncle. The peduncle can range from pale yellow to purple-brown in colour, and is sometimes even a bright blue. The capitulum is made up of 5 large thin white shell plates. These plates are delicate and have broad ridges. They can be so thin they are almost translucent. If the secreted float is present it has a very distinctive polystyrene-like texture.

Habitat: Found attached to floating seaweed, feathers and other very small debris, including Vellela velella. Can also secrete its own float.

Distribution: Recorded washed up around SW Britain and west Scotland, as well as on the west coast of Ireland, extending as far as Rathlin Island and the north coast of Northern Ireland.

Similar Species: Could be confused with some of the other species of goose barnacles found attached to floating debris but this species has a very short peduncle.

Key Identification Features:

• Goose barnacle that can grow up to 7 cm total length, but has a very short peduncle.
• Capitulum made up of 5 very thin (almost translucent at times) white plates.
• Only species that can secrete its own float, which if present is very distinctive and has a polystyrene-like texture.

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

iNaturalist: Dosima fascicularis at iNaturalist World Species Observations database.

GBIF data for Dosima fascicularis

WoRMS: Dosima fascicularis at World Register of Marine Species. Accepted name: Dosima fascicularis (Ellis & Solander, 1786). AphiaID: 106148.

Classification: Biota; Animalia; Arthropoda; Crustacea; Multicrustacea; Thecostraca; Cirripedia; Thoracica; Thoracicalcarea; Scalpellomorpha; Lepadoidea; Lepadidae; Dosima