A bryozoan (Cylindroporella tubulosa)

Distribution data supplied by the Ocean Biodiversity Information System (OBIS). To interrogate UK data visit the NBN Atlas.Map Help



Colonies form small round patches and encrust hard surfaces. Zooids are small (0.50 to 0.63 mm in length by 0.3 mm in width) and rhombic or oval in shape. The frontal surface is slightly raised with numerous pores. The primary orifice is located at the top (distal) end of the zooid, is round and completely encircled by a calcified elevated ridge (peristome). The peristome orifice is circular with a series of projections at various intervals. A semi-circular pore is situated at the base of the peristome. Young zooids located at the margins of the colony have 4 thin, long spines at the distal margin of the primary orifice. Ovicells are present and are round and raised with the surface covered in small pores. There are no avicularia.

Recorded distribution in Britain and Ireland

A very rare species in the British Isles with isolated records in the Shetland Islands and Loch Eriboll, Scotland. These localities probably reflect the southern limit of this species.

Global distribution

An Arctic, circumpolar species. It has been recorded around the Barents, Kara, Chukotsk, Bering and Okhotsk Seas, Norway, Greenland, the northern coast of North America and the Archipelago of the Canadian Islands.


This species lives on seaweed, ascidians, shells and stones at depths of 5 to 230 m.

Depth range


Identifying features

  • Colonies form small round patches.
  • The frontal wall of the zooid has numerous pores.
  • The peristome extends from the primary orifice and has a small hole at the base.
  • A series of points often project from the rim of the peristome.
  • Ovicells are present and situated behind the primary orifice.
  • Zooids are oval or rhomboidal in shape.

Additional information

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  1. Hayward, P.J. & Ryland, J.S. 1999. Cheilostomatous Bryozoa. Part II Hippothooidea - Celleporoidea. London: Academic Press. [Synopses of the British Fauna, no. 14. (2nd edition)]

  2. Howson, C.M. & Picton, B.E., 1997. The species directory of the marine fauna and flora of the British Isles and surrounding seas. Belfast: Ulster Museum. [Ulster Museum publication, no. 276.]

  3. JNCC (Joint Nature Conservation Committee), 1999. Marine Environment Resource Mapping And Information Database (MERMAID): Marine Nature Conservation Review Survey Database. [on-line] http://www.jncc.gov.uk/mermaid

  4. Kluge, G.A., 1975. Bryozoa of the Northern Seas of the USSR. New Delhi: Amerind Publishing Co. Pvt. Ltd


  1. NBN (National Biodiversity Network) Atlas. Available from: https://www.nbnatlas.org.

  2. OBIS (Ocean Biodiversity Information System),  2024. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. www.iobis.org. Accessed: 2024-06-15


This review can be cited as:

Carter, M.C. 2003. Cylindroporella tubulosa A bryozoan. In Tyler-Walters H. and Hiscock K. Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 15-06-2024]. Available from: https://www.marlin.ac.uk/species/detail/1961

Last Updated: 10/09/2003