Aggregating Anemone     Anthopleura elegantissima


Pulled down into the sand during low tide, these anemones are really attached to underlying large cobbles or rocks.


A relative of the Giant Green anemone and the Moon Glow anemone, the Aggregating anemone sports a similar green (due to algae), bumpy body, however it has pale green tentacles with reddish tips that lack white stripes.  The main characteristic of this species is it's habit of usually occurring in large colonies.  These colonies are mainly composed of clones or genetically identical individuals that split off the original individual.  They also reproduce sexually.  When more than one genetically distinct set of clones inhabits a rock, fighting between the clones is intense causing a visible open space between them.  Fighting is done through the use of specialized stinging structures at the base of the tentacles.  


Individuals in colonies are usually two to three inches in diameter while isolated individuals may grow to 10 inches.  They are usually found in more exposed, high current areas in the mid to low intertidal zone attached to rocky boulders or in tide pools.  They range from Alaska to northern Mexico.


They feed on a variety of animals that wander into their tentacles.  They are fed upon by the shaggy mouse nudibranch and the leather sea star.