Membranipora membranacea

The Lacy-Crust Bryozoans

Phylum Bryozoa
Class Gymnolaemata 
Order Cheilostomata Suborder Anaska 
Family Membraniporidae 
Genus Membranipora
Species membranacea

Description: Forms white, disc-like colonies, approx. 1 mm high and up to and over 100 mm wide. Zooids are rectangular and fit together neatly in radially arranged rows that grow outward and branch into new rows as the pattern grows wider.

Habitat: Found encrustating on kelps and other large seaweeds, especially common on the brown algae Laminaria, but can also be found growing on rocks, glass, floats or other smooth surfaces.

Natural History: Colonies are made up of hundreds or thousands of individual zooids, which are not much larger than a pin head. Their eight week growing season falls between late spring and early autumn. During this time, how they grow is dependent upon their success in the competition for space. The interaction between colonies can be cooperative to aggressive depending upon their size. Small colonies communicate by using electrical signals. Large colonies use runners called stolons from which new zoids bud from to mediate aggressive behaviors.