Disporella separata Osborn, 1953

Common name(s): Purple encrusting bryozoan

Phylum Bryozoa (Ectoprocta)
Class Stenolaemata
Order Cyclostomata
Suborder Rectangulata
Family Lichenoporidae
A Disporella separata colony from 10 m depth, Burrows Channel.  The colony is 5 cm across and there are several tubeworms living in it, extending their tentacles.
(Photo by: Dave Cowles, July 2007)
Description:  This beautifully colored bryozoan forms a hard patchlike, encrusting colony.  The colony is really a cluster of calcified tubes which are largely covered over but their cylindrical ends are exposed at the end of many of the zooids (photo).  The apertures of the zooids are circular and have no operculum.  They have no avicularia or spines.  In this species, which can grow to 10 cm or more in diameter, the zooids are arranged in subgroups composed of circular bundles of 10-12 groups of elevated zooids each (photo).  In my observations, there are also non-elevated zooids within and between the circles.  The color is often a strong purple.

How to Distinguish from Similar Species:  The colony at first glance may look like a purple sponge, but it is hard and the circular clusters of zooecia can be seen without magnification (see above).  Several other species such as Disporella fimbriata form small colonies not divided into subclusters and not colored purple.

Geographical Range: From British Columbia to southern California

Depth Range:


Biology/Natural History:



Dichotomous Keys:
  Kozloff 1987, 1996

General References:

Scientific Articles:
Type articles in this span

Web sites:

General Notes and Observations:  Locations, abundances, unusual behaviors:

In this closeup view the individual zooids can be seen.  The surface of the colony is covered with circular clusters of groups of elevated zooids with non-elevated zooids between and within the circles.

Another view also shows the circular groups of clusters of elevated zooecia.

A dead patch on the colony clearly shows the encrusted tubes the colony is made of

Authors and Editors of Page:
Dave Cowles (2007):  Created original page
CSS coding for page developed by Jonathan Cowles (2007)