MarLIN

information on the biology of species and the ecology of habitats found around the coasts and seas of the British Isles

A sea mat (Schizoporella unicornis)

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

Summary

Description

Schizoporella unicornis forms sheets with one or more layers of zooids on various substrata on the lower shore. The whitish or pink colonies coat hard surfaces such as stones and shells or the holdfasts of large algae (e.g. Himanthalia and Laminaria). The zooids are arranged in a regular pattern. Individual zooids are convex, usually rectangular in shape, and typically 0.4 - 0.7 mm x 0.3 - 0.5 mm in size. Deep grooves mark the boundaries between the zooids. Each zooid has a D-shaped orifice with a V-shaped indentation in the middle of the straight edge. A single or pair of raised avicularia sit either side of the orifice. Later in development, a conical umbo (small projection) appears directly below the V-shaped sinus of each primary orifice. 

Recorded distribution in Britain and Ireland

Common on all British and Irish coasts, although under reported on some coasts (particularly around Ireland).

Global distribution

Schizoporella unicornis is scattered circumglobally, mainly in temperate coastal regions. Most records are located in the northern hemisphere, with colonies commonly occurring on the West and East coasts of the USA, the British Isles and the Northeastern Mediterranean. However, it has also been recorded in the tropics (e.g. Hawaii and Port Sudan). In the southern hemisphere, Schizoporella unicornis has been found at a single location near Curitiba, Brazil.

Habitat

Colonizes a variety of substrata from the lower shore to the shallow sublittoral. These include the underside of rocks and shells, Himanthalia buttons and Laminaria holdfasts. 

Depth range

Lower Shore - Shallow Sublittoral

Identifying features

  • Polygonous (typically rectangular) zooids, approximately 0.4 - 0.7 mm x 0.3 - 0.5 mm.
  • Colonies form uni or multilaminar sheets. 
  • Primary orifices are D-shaped and wider than long. 
  • Polypide has 21-24 tentacles.
  • Ovicell is globular and lacks pores (imperforate).
  • Avicularia with acute triangular rostra are present either singularly or in pairs on each zooid.
  • External surface of zooids is densely perforated by round pores. 

Additional information

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Further information sources

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Bibliography

  1. Hayward, P.J. & Ryland, J.S. (ed.) 1995a. The marine fauna of the British Isles and north-west Europe. Volume 2. Molluscs to Chordates. Oxford Science Publications. Oxford: Clarendon Press.

  2. 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)]

  3. Porter, J., 2012. Seasearch Guide to Bryozoans and Hydroids of Britain and Ireland.   Ross-on-Wye: Marine Conservation Society.

Citation

This review can be cited as:

Wilson, C.M. 2017. Schizoporella unicornis A sea mat. In Tyler-Walters H. and Hiscock K. (eds) Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. Available from: http://www.marlin.ac.uk/species/detail/2314

Last Updated: 10/10/2017

Tags: Bryozoa bryozoan