How to Distinguish from Similar Species: In Eudistylia catharinae the notopodia of the first few abdominal segments are shorter than the tori of the posterior thoracic segments. In Eudistylia polymorpha the dorsal edges of both lobes from which the radioles originate have a cleft; plus its prostomial cirri are reddish brown to maroon and tipped with orange. Other species also do not have the distinctive green and maroon bands on their radioles.
Geographical Range: Alaska to central California
Depth Range: Low intertidal to 20 m
Habitat: Often in large clusters attached to crevices of boulders and bedrock, or on floats or pilings; and on vertical rock faces and surge channels in heavy surf.
Biology/Natural History: Although they do not have large ocelli as found in some other plumeworms, this species is highly light sensitive and will withdraw quickly into the tube if a shadow passes over it. Often anemones are found feeding near the top of the tube. This species may hybridize with Eudistylia polymorpha. Its blood contains chlorocruorin instead of hemoglobin. They can regenerate their radioles if a predator nips them off. However, they do not appear to be able to re-build a tube if removed from it (Merz, 2015).
The radioles of members
of Family Sabellidae contain a food groove
with a stepped cross-section that serves as a size-filter. The smallest
particles, which fit in all the way to the bottom of the groove, are usually
eaten. Moderate size particles, in the upper parts of the groove,
are often glued together to build the tube. The largest particles,
too large to fit within the groove, are usually rejected. The radioles
are also used for gas exchange (like gills) but the circulatory pattern
within them is unusual. Instead of having afferent and efferent vessels,
the radioles have a
single branchial vessel in each radiole which the blood flows in and out
of. Sabellids possess giant nerve
fibers running down their body which allows them to retract rapidly into
their tube if disturbed.
Kozloff 1987, 1996
Smith and Carlton, 1975
General Notes and Observations: Locations, abundances, unusual behaviors:
Authors and Editors of Page:
Dave Cowles (2005): Created original page