Pachycerianthus fimbriatus McMurrich, 1910
Common name(s): Tubedwelling anemone
|Synonyms: Pachycerianthus torreyi, P. plicatulus|
|Pachycerianthus fimbriatus photographed at Monterey Bay Aquarium. Tentacle spread is approximately 30 cm.|
|(Photo by: Dave Cowles, August 2010)|
Description: This anemone-like species lives in a slippery black tube that they secrete. It has two rings of slender, translucent brownish, purplish-black, orange, or light colored tentacles. The inner ring may be held over the mouth while the outer ring is extended further. Animal length to 35 cm. Tube up to about 2.5 cm diameter and may be more than a meter long.
How to Distinguish from Similar Species: This is the only member of this Subclass in our area. Other members of the subclass include black corals
Geographical Range: Southern Alaska to Isla San Martin, Baja California
Depth Range: Rarely intertidal, mostly subtidal to at least 54 m
Habitat: Very soft mud such as bays and harbors. Sometimes in sand.
This anemone-like cerianthid lives in a soft, black, slimy tube that
may extend a meter or farther into the sediment. The tube
extends slightly above the sediment and is
made of a secretion of nematocyst-like organelles called ptychocysts.
The cerianthid quickly withdraws into the tube when
disturbed, and may leave a star-shaped track in the mud around the tube
entrance with its tentacles when it withdraws. Predators
include the nudibranch Dendronotus
iris, which may be drawn into the tube and continue
feeding when the cerianthid withdraws. Dendronotus iris
attaches its eggs to the tube of the cerianthid, which appears to be
its principal prey. Feeding by the nudibranch usually does not
kill the cerianthid. The aboral end of the
cerianthid is pointed and adapted to digging. Cerianthids differ
from anemones in several ways, such as having an aboral anal pore.
Cerianthids have unusually rapidly-conducting nervous systems
for Anthozoans. Some cerianthids have fluorescent tentacles.
|Main Page||Alphabetic Index||Systematic Index||Glossary|
Hinton, 1987 (as P. estuari)
Lamb and Hanby, 2005
Morris et al., 1980
Ricketts et al., 1985
General Notes and
abundances, unusual behaviors:
I have not observed this species near Rosario, where bottoms are sandy or rocky. It may be found in quieter, muddier bays.
Rosario Invertebrates web site provided courtesy of Walla Walla University