Description: This bryozoan has an erect, flexible bushlike colony with spiraling whorled branches (photo) instead of being encrusting. Although the colony is flexible it is partly stiffened (lightly calcified). The branches are attached directly to the substrate rather than arising from a long stalk. The zooids are in double rows, with more rows near where the colony branches. Each zooid ends with two large, blunt spines. Much of the frontal of the zooecia is not calcified. It has no vibracula nor scutum. Large avicularia which look like birds' heads are present near the center of the zooids (photo) but not on the frontals. The ovicells are globular (photo). Colonies up to 5 cm or more tall, with zooids 0.5 to 0.6 mm tall. Whitish or tan; parts may appear orange during sexual reproduction. Ricketts et al., (1985) says they sometimes have a purplish tinge.
How to Distinguish from Similar Species:Bugula pugeti, B. cucullifera, andB. pacifica do not have branches in spiral whorls.
Geographical Range: British Columbia, Canada to Galapagos Islands, Hawaii. Especially common on the Channel Islands in California.
Depth Range: Subtidal to 400 m depth, most common to 60-70 m.
Habitat: Attach to hard substrates. Common on docks and floats. Members of this genus are important boat fouling organisms.
parts of the colony may consist mostly of dead zooids,
which may appear dark brown. The birdhead-like avicularia
keep other organisms from settling on the colony, plus may also capture
small crustaceans which are then passed to the mouth of the zooids.
In Los Angeles harbor reproduction is year-round but in colder waters
is concentrated during the warmer months. The larvae may be
for only a short time--4-6 hours; then settles as an ancestrula which
repeatedly to form the colony. Predators include the clown
catalinae. Other nudibranchs such
albolineata and Janolus
fuscus feed on Bugula
species as well so may be predators on this species.
Flora and Fairbanks, 1966
Kozloff, 1987, 1996
General Notes and Observations: Locations, abundances, unusual behaviors:
Authors and Editors of Page:
Dave Cowles (2012): Created original page
CSS coding for page developed by Jonathan Cowles (2007)
Salish Sea Invertebrates web site provided courtesy of Walla Walla University