Biology/Natural History: Bryozoans start from a single individual zooid (an ancestrula) which repeatedly reproduces asexually to form a colony. In this species, the oldest individual is in the middle. Colonies of this species usually begin to be noticeable in late spring and grow through summer into fall. By fall they may form extensive crusts on the kelp and many colonies have merged with one another. In many bryozoans there are various types of zooids but in this species there is only one type of zooid which serves for feeding, for reproduction, and for defense. The colony appears to be a simultaneous hermaphrodite, or male zooids may develop first. They do not brood their young. Eggs are fertilized then released, and quickly develop into cyphonautes larvae which may feed and develop as plankton for several months. The larvae settle when they encounter kelp such as Laminaria or water with an excess of potassium ions. The small white nudibranch Doridella steinbergae may be found living and feeding on these colonies but it blends in so well it is difficult to see. Other predators include sea urchins and the nudibranch Corambe pacifica (pale translucent gray with a central yellowish patch and marginal yellow lines, up to 1 cm long, nearly as wide as long, with a deep notch in back). Colonies which have recently been attacked by nudibranchs may grow large chitonous spines, especially on the peripheral zooids.
This species appears to be able to feed at higher water flow velocities than some other species can (Pratt, 2008). They frequently encrust the brown kelp Nereocystis luetkeana, and the larvae show a strong preference to settling on that alga over the red alga Mazzaella splendens (Matson et al., 2010). The Matson et al. article includes online several videos showing larval settlement in flow.