Calpensia nobilis (Esper, 1796)

Calpensia nobilis is an encrusting bryozoan, found in warm temperate waters. The colonies form thin, flattened broad sheets, or thick cylindrical incrustations. The colonies are pale brown in colour and often very extensive, up to 10 cm2  or more. Successive growth may produce colonies which are composed of many layers of autozooids. Autozooids are rectangular and are arranged in a regular linear series. They are typically 0.7 – 0.8 by 0.30 – 0.4 mm.

The species is able to colonise shell debris, stones and various organic substrates. It grows epiphytically on Posidonia seagrass. It ranges from 10 to 60 m, but is rarely found deeper.

Calpensia nobilis is distributed in warm temperate waters and is present throughout the Mediterranean and in the eastern Atlantic. Its northerly limit seems to be the Channel Islands.