Anthopleura artemisia (Pickering in Dana, 1848)

Common name(s): Burrowing anemone, Burrowing green anemone, Buried anemone, Moonglow anemone

Synonyms: On Seal Beach
Phylum Cnidaria
 Class Anthozoa
  Subclass Zoantharia
   Order Actniniaria
    Family Actiniidae
Anthopleura artemisia, photographed at Seal Beach, CA in a piddock clam hole.  The anemone was mostly covered by sand, as is common for this species.  I swirled away the sand before taking this picture.
Photo by: Dave Cowles, Sept 2010
Description: Typically lives partly buried in sand or shells but base of column is attached to a rock under the sediment.  No acontiaTubercles are restricted to the upper two thirds of the column so lower part of column is smooth and white or pink (photo).  Oral disk may be bright pink, orange, or green.  Tentacles may be solidly colored or banded, and may be red, white, black, blue, gray, brown, or green (in SE Alaska they are usually green).  The bands on tentacles (if present) are usually white.  The outer margins of the oral disk (outside the ring of tentacles) contain white spherules for fighting, as do the other Anthopleura species (these spherules are often hard to see).  There may be bright spots of color at the base of the tentacles (photo).

How to Distinguish from Similar Species: Both A. elegantissima and A. xanthogrammica have tubercles and symbionts all the way to the bottom of the column, and live on rock or protrude through only a little sand. Some sources say that A. artemisia does not have symbiotic algae while most individuals of these other species do.

Geographical Range:  Alaska to southern California.  Very common around Juneau, Alaska.

Depth Range:  Low intertidal and subtidal to about 30 meters

Habitat:  Open coast and (more often) in protected bays, prefers habitats with rocks or cobble buried in sand.

Biology/Natural History:  Normally only the tentacles and oral disk are exposed, with the rest of the anemone buried in the sediment.  This species is capable of greatly elongating.  At low tide the anemone may withdraw below the surface of the sediment.  Sometimes they live in holes made by boring clams (see photo above, for example).  Individuals are solitary as in A. xanthogrammica, but they can divide asexually by longitudinal fission as in A. elegantissima.  They will attack other individuals who are nearby using their special white spherule tentacles.  I find this species much less commonly than the two other species.  Some references say they contain algal symbionts, but some recent information suggests that they do not even though they may sometimes be green in color.  In British Columbia this species has been observed feeding on spawned herring eggs.
Types of cnidae in A. artemisia: Spirocysts, atrichs, basitrichs, and microbasic p-mastigophores.

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Dichotomous Keys:
Kozloff 1987, Marine Invertebrates of the Pacific Northwest Anthopleura_artemisia_DLC2020-03s.jpg
Smith and Carlton, 1975.  Light's Manual: Intertidal Invertebrates of the Central California Coast

General References:
Morris, Abbott, and Haderlie, 1980.  Intertidal Invertebrates of California.  Stanford University Press.
O’Clair and O’Clair, 1998.  Southeast Alaska’s Rocky Shores.  Plant Press.
Flora and Fairbanks, 1966.  The Sound and the Sea
Kozloff, 1993, Seashore Life of the Northern Pacific Coast

Scientific Articles:

Hand, Cadet, 1955.  The sea anemones of central California part II.  The endomyarian and mesomyarian anemones.  The Wasmann Journal of Biology 13:1 pp. 37-99

General Notes and Observations:  Locations, abundances, unusual behaviors, etc.:
  This species seems to be much less common than either A. elegantissima or A. xanthogrammica, at least south of Alaska

This individual was buried in find sand/mud and attached to a shell at Guemes Channel near Guemes Ferry, Anacortes, WA.  Photo by Dave Cowles, July 2005

This photo shows the column and tubercles of the Guemes Channel individual above.
Photo by Dave Cowles, July 2005 

In crevice

This small individual was photographed in a crevice on a boulder high in the intertidal (but subject to frequent wave spray and runoff) on Beach #4 near Kalaloch, WA.
Photograph by Dave Cowles.  See finger for scale.
The photos below are of an Anthopleura artemisia anemone about 5 cm diameter found in a low-intertidal salt creek at Penn Cove, July 2020. Photos by Dave Cowles
Whole individual
View of the whole individual. This anemone was immersed as a solitary individual in a fast-flowing tidal creek at low tide, attached to a shell fragment nearly 10 cm below the sediment surface with only the oral disk and tentacles protruding.
This side view shows the abundant adhesive tubercles on the upper column (holding onto bits of sand and shell fragments) but the lack of tubercles on the lower column wall.
This closeup shows the pattern on the oral disk and tentacles.
Closeup of tentacle base and column wall
In this closeup of the upper column wall and base of the tentacles, it can be seen that the white spherule-shaped "attack" tentacles sometimes visible here are currently retracted. Notice how the green color of the column and tentacles is much paler than normally seen in A. elegantissima or A. xanthogrammica. Those species are green because of symbiotic algae, while this species has been said to have none so this green would be an animal pigment.

Authors and Editors of Page:
Dave Cowles, 2004, 2005