Disporella separata Osburn 1953

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. 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. 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. 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