subtidal anemone has
tubercles on the column wall (see picture), usually a cream or orange
tentacles orange and sometimes banded but with no white spots at their
bases. The column is often more than 5 cm high and can
much higher than it is wide. Sometimes the anemone has darker
or red blotches or streaks (picture).
anemone has at least 160 tentacles in individuals of over 5 cm column
Stomphia didemon Siebert,
Common name(s): Orange
anemone. Swimming anemone.
|Stomphia didemon, about 3.5 cm
diameter and 4 cm tall.
Captured by otter trawl at about 90 m depth from San Juan Channel
|Photo by: Dave Cowles July
How to Distinguish from
Similar Species: Stomphia
coccinea has a whitish column with red or
orange-red streaks, is
not usually more than 3 cm high, and usually is found on horse mussel (Modiolus
modiolus) shells. Stomphia sp.
has less than 130 tentacles
on individuals 5 cm or more tall, and its color is a uniform reddish
Range: Web sources indicate
that it can be found at least in Alaska, British Columbia, and
Depth Range: The
Monterey Bay Aquarium
reports that this species lives from 60-180 m depth
the San Juan channel specimens
are often captured from sand/gravel bottoms at about 80-100 m
They usually come up not attached to anything, though they will readily
attach to a solid object in an aquarium. Perhaps this is
they have a swimming response to predators.
History: Little is
known. This is a recently described species. The
species in general is strong enough that the upper part of the body can
cover the tentacles (the tentacles can be retracted completely
This species, as well as a relative Stomphia coccinea,
to detach from the bottom and swim away from predators such as the
star, Dermasterias imbricata. S.
coccinea is found
in northern boreal waters of the Atlantic and Pacific.
selaginella, inhabits McMurdo Sound in Antarctica.
On one web site
the BBC reports on S. didemon: "When approached by
a predatory leather
star, this anemone, Stomphia didemon, became highly
elongated and swayed from side to side. Then, bending low, it brushed
tentacles over the leather star. Finally, this normally sedentary
inflated a muscular cone at its base to lever itself free from its
and danced away in the water column."
The species is said to eat small crustaceans.
http://www.underwater-photos.com/pw046.html (a photo and short note
on S. coccinea)
http://www.ups.edu/faculty/jkelliott/escape.htm (photos and description
of S. didemon escaping from the leather star)
Dalby, J. Jr., J. K. Elliott, and D. M. Ross. 1988. The
of the actinian Stomphia didemon to certain
and phylogenetic implications. Can. J. Zool. 66: 2484-2491.
General Notes and
Observations: Locations, abundances,
unusual behaviors, etc.:
We have usually caught this species by otter trawl in the San Juan
Channel north of San Juan Island, using the Friday Harbor Marine Lab
Stomphia didemon's column wall. This
species has no tubercles
the wall. A few bits of debris may be present but they appear
be just loosely attached by mucus.
Another individual. Captured 100 m depth, San Juan
Photo by Dave Cowles, July 2000
A view of the oral disk. Photo by Dave Cowles, July 2000
This individual from 100 m, San Juan Channel, is perched on a shell.
The tentacles end with a small pore.
An unusually pale individual.
Authors and Editors of Page:
Dave Cowles (2004): Created original page