Anthopleura sola Pearse and Francis, 2000

Common name(s): Sunburst Anemone

Synonyms:  Cribrina elegantissima,
Bunodactis elegantissima, Anthopleura elegantissima (solitary form)
Phylum Cnidaria
 Class Anthozoa
  Subclass Zoantharia
   Order Actniniaria
    Family Actiniidae
Acanthopleura sola at Little Corona del Mar, CA. About 12 cm diameter 
Photo by: Dave Cowles, 3-2005
Description:  This species looks very similar to Anthopleura elegantissima, and formerly was simply identified as a solitary form of A. elegantissima.  Pearse and Francis identified it as a separate species by molecular techniques in 2000.  This species grows larger than A. elegantissima usually does (up to 25 cm wide), and is not normally found in contact with or even very near A. elegantissima.  Cylindrical.  The column is pale gray-green to white and twice as long as wide when completely extended; pale, variously colored tentacles with pink, lavender, or blue tips, in 5 rings around oral disk and are numerous, thick, and pointed.  The anemone has a ring of knobs (acrorhagia) with stinging cells just under and outside the ring of tentacles (photo). When the anemones are not fighting the acrorhagia are usually retracted and hard to see.  The column is covered with vertical rows of adhesive tubercles or verrucae (picture).  One can distinguish the species from A. xanthogrammica by their branched verrucae, coloration (especially colored tips of the tentacles and clearly marked stripes on the oral disk), and the fact that their adhesive tubercles are arranged in vertical rows while those of A. xanthogrammica are not.  Most individuals are at least 3 cm in diameter, and average 12 cm.

How to Distinguish from Similar Species: : It is similar to Anthopleura xanthogrammica, which is all green.  Anthopleura artemisia has verrucae on only the top 2/3 of its column and usually lives mostly buried in sand. Anthopleura elegantissima is usually smaller and usually is found in clonal groups rather than solitary.

Geographical Range: From Central California to Baja California

Depth Range: Live in the lower intertidal zone.

Habitat: Rocky intertidal areas on the outer coast.

Biology/Natural History: Background color is due in part to zooxanthellae living symbiotically in the gastrodermal layer.  This species is found in similar situations as is Anthopleura xanthogrammica farther north on the Pacific coast.

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Dichotomous Keys:  (In all these keys this species keys as A. elegantissima)
Allen, 1976
Kozloff 1987, 1996
Smith and Carlton, 1975

General References:

Scientific Articles:

Francis, Lisbeth, 1979.  Contrast between solitary and clonal lifestyles in the sea anemone Anthopleura elegantissima.  American Zoologist 19: 669-681

McFadden, C.S., R.K. Grosberg, B. B. Cameron, D. P. Karlton, and D. Secord, 1997.  Genetic relationships within and between clonal and solitary forms of the sea anemone Anthopleura elegantissima revisited:  evidence for the existence of two species.  Marine Biology 128: 127-139

Pearse, V.  and L. Francis (2000) Anthopleura sola, a new species, solitary sibling species to the aggregating sea anemone, A. elegantissima (Cnidaria: Anthozoa: Actiniaria: Actiniidae). Proc Biol Soc Washington 113: 596-608

Smith, B.L. and D.C. Potts, 1987.  Clonal and solitary anemones (Anthopleura) of western North America:  population genetics and systematics.  Marine Biology 94: 537-546

General Notes and Observations:  Locations, abundances, unusual behaviors, etc.:

This species has wide variety of color variations on the oral disk.  Here are two:

Photographed at Moss Street Beach, Laguna, CA by Dave Cowles, March 2005.  Diameter of the large anemone is about 15 cm.  Note the white spots that are frequently found on the tentacles of this species.

This individual has its mouth open, and the filmy "lips" can be seen.

Photo by Dave Cowles, Little Corona del Mar, CA, March 2005

Frilly lips

Holding the frilly lips loosely is common with A. sola, as seen also in this individual at Laguna Beach, CA.  A. xanthogrammica is a similar sized anemone but seldom holds its lips like this.  Photo by Dave Cowles, August 2010

This species favors sheltered microhabitats.  On rocks with cracks, such as this one at Dana Point, CA, the anemones can be found in lines along the crack.
Photo by Dave Cowles, March 2005

The crack need not even be very large.  Note the row of A. sola on this rock at Little Corona del Mar, CA.  Photo by Dave Cowles, March 2005  Note also that the anemones
have covered themselves with bits of shell.

The column of Anthopleura sola is covered with  rows of tubercles (verrucae), many of which attach to bits of rock or shell.
Photo by Dave Cowles at Little Corona del Mar, CA, March 2005

Aligned tubercles

This photo of a closed individual at Laguna Beach, CA also shows the verrucae pattern.  Photo by Dave Cowles, 2010

This is a picture of two A elegantissima or A. sola fighting, using their specialized white tentacles called acrorhagia.
Normally the acrorhagia are small and hardly visible near the base of the normal, green tentacles.
Taken at San Simeon, CA by Dave Cowles in a tidepool.

This A. sola (about 13 cm diamter) is attacking an Aplysia sea hare in a Dana Point, Ca tide pool.  Note the ink released from the sea hare.
This is the only time I have seen this anemone species attacking a sea hare.  It appears the sea hare wandered onto the anemone.  The sea hare later died, but I did not see whether the anemone swallowed it.
Photo by Dave Cowles 5-99

This individual was photographed by Charles Hollahan of Santa Barbara Marine Biologicals at about 3m depth off Coal Oil Point, Santa Barbara, CA in 2005.  Note the unusual blue tentacle tips.

Authors and Editors of Page:
Dave Cowles, 2005