How to Distinguish from Similar Species: Epiactis prolifera is usually smaller and has narrow radiating white lines on the oral disk which originate close to the mouth, (the radiating dark lines on the edges of the pedal disk come up the column only partially as in this species), and brood their young externally.Epiactis lisbethae also has narrow white lines on the oral disk which continue to the mouth, and also has darker lines on the column which continue all the way up to the top. Cribrinopsis ritteri has radiating lines on the oral disk but the lines are red and the column has tubercles. This species can look superficially like an aposymbiotic Anthopleura elegantissima but its column tubercles are not in vertical rows and A. elegantissima is not found this flat.
Geographical Range: Alaska to central California. Said to be common on the open coast though I have rarely seen it.
Depth Range: Low intertidal (and probably subtidal)
Habitat: Usually under rocks in the lower intertidal.
Biology/Natural History: This species is extremely flat when contracted (see pictures). The unusual pale coloration of some individuals (see photos) may be due to the fact that they are in a sea cave. This species broods its young internally. The red-orange red eggs are about 1/2 mm in diameter and are fertilized inside the parent. Once they have grown to a size sufficient to have tentacles, they leave the mouth and crawl away. Asexual reproduction is not known to occur.
Dichotomous Keys:Kozloff, 1987, 1996
Edmands, Suzanne, 1994. Genetic and Evolutionary Consequences of Various Reproductive Strategies in the Sea Anemone Genus Epiactis. Ph.D. Dissertation, University of California at Santa Cruz (USA), 187 pp.
Edmands, S. and D. C. Potts, 1997. Population genetic structure in brooding sea anemones (Epiactis spp) with contrasting reproductive modes. Marine Biology 127: 485-498.
Hand, Cadet and Daphne Fautin Dunn. 1974. Redescription and
of the sea anemone Cnidopus ritteri (Torrey)
Wasmann Journal of Biology 32(2): 187-194.
General Notes and Observations: Locations, abundances, unusual behaviors, etc.:
Authors and Editors of Page:
Dave Cowles (2004): Created original page