Attack of the Clones

Sea anemones fight territorial disputes based on genetics

• Hannah Schardt
• Dec 01, 2005

DURING HIGH TIDE, genetically homogeneous colonies--called clones--of the sea anemone Anthopleura elegantissima send out well-armed "warriors" to the edge of their territory to battle other, genetically distinct clones. Now researchers in California and Australia have found the battle isn't limited to the front lines; polyps four or five rows back will reach over and attack members of another clone. Surprisingly, these warrior polyps are genetically identical to the peaceful "breeder" polyps that live at the center of the colony--proof, says University of California-Davis researcher Rick Grosberg, that environment, not genetics, determines which polyps become fighters.