Anthopleura (Anthopleura.htm)

Anthopleura elegantissima (Brandt, 1835)

(Previously known as Cribina elegantissima, Bunodactis elegantissima)

Aggregating Anemone/A. sola

Anthopleura elegantissima anemone

General Description (from Morris et al. 1980 and Kendall et al. 2002):

A. elegantissima is colonial with radiating lines on oral disk; up to 8cm across tentacular crown (generally smaller than A. sola); tentacles greenish to pinkish in color

A. sola is solitary with radiating lines on oral disk; up to 25 cm across tentacular crown; previously thought to be the same species as A. elegantissima, but now recognized as a sibling species (Pearse and Francis 2000); small individuals located relatively closely together can be confused w/ A. elegantissima and have been grouped together for MARINE monitoring

Anthopleura elegantissima
Photo: Richard Herrman

Habitat and Range (from Morris et al. 1980):

Abundant on rock, in tidepools or crevices, on pier pilings; characteristic of middle intertidal zone of semiprotected rocky shores of both bays and outer coasts; Alaska to Baja California

Anthopleura sola Photo: John Engle

Biology:

Aggregating anemones are so abundant most likely due to their ability to produce clones of themselves by longitudinal fission (Sebens 1982). Non-clonemates are spatially separated after aggressive stinging battles (Raimondi et al. 1999). The green and olive colors come from symbiotic unicellular algae (Kozloff 1983). When exposed to air, these anemones contract their tentacles inward to their oral disk, leaving only the exterior surface of the stalk visible. This surface is covered with shell fragments to prevent desiccation. If they are squished in this closed position, water squirts out the oral cavity and through pores in the stalk. Aggregating anemones are resistant to sand scouring and burial (Raimondi et al. 1999). They can survive for more than 3 months if buried with sand by metabolizing their own body tissue (Sebens 1980). After major disturbances, such as oil spills, recovery may take 1-2 years or more (Raimondi et al. 1999; also, see Vesco and Gillard 1980).

Anthopleura sola

Anthopleura elegantissima

Anthopleura sola

Anthopleura elegantissima(left) and Anthopleura xanthogrammica (right) (illustration by Kelly Donovan after Smith and Carlton 1975)

Can be confused with:

A. xanthogrammica, which has a solid green oral disk and a firmer stalk when withdrawn; also has small, closely arranged, irregularly shaped tubercles on the column (as opposed to A. sola which has prominent rounded bumps arranged in rows); A. xanthogrammica has a tighter sphincter muscle than A. sola (Morris et al. 1980); ranges southward at least to Baja (reportedly to Panama), but is rare south of Point Conception, where it is found only in cooler-water upwelling areas (Engle pers comm)

A. sola is found alone with no nearby A. elegantissima; if a small anemone is found with A. elegantissima nearby, but not touching it, it is most likely A. elegantissima (Kendall et al. 2002)

Anthopleura xanthogrammica

References:

Morris RH, Abbott DL, Haderlie EC (1980). Intertidal invertebrates of California. Stanford University Press, Stanford

Kendall A, Kusic K, Maloney E, Williams M (2002) List of species to be discussed at the 2002 MMS Taxonomic Workshop

Kozloff EN (1983) Seashore life of the northern Pacific coast. University of Washington Press, Seattle

Pearse V and Francis L (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

Raimondi PT, Ambrose RF, Engle JM, Murray SN, Wilson M (1999) Monitoring of rocky intertidal resources along the central and southern California mainland. 3-Year Report for San Luis Obispo, Santa Barbara, and Orange Counties (Fall 1995-Spring 1998). OCS Study, MMS 99-0032, U.S. Bureau of Energy Management, Regulation, and Enforcement, Pacific OCS Region

Sebens KP (1980) The regulation of asexual reproduction and indeterminate body size in the sea anemone Anthopleura elegantissima (Brandt). Biol Bull 158:370-382

Smith RI and Carlton JT (1975) Light's manual: intertidal invertebrates of the central California coast. Univ of Ca Press, Berkeley and Los Angeles, Ca

Vesco LL and Gillard R (1980) Recovery of benthic marine populations along the Pacific Coast of the United States following man-made and natural disturbances including pertinent life history information. U.S. Department of the Interior, Bureau of Land Management Service, POCS Reference Paper No. 53-4