Researchers say they've found clashing colonies of sea anemones fight as organized armies, with distinct castes of warriors, scouts and other types.
Sea anemones -- Anthopleura elegantissima -- live in large colonies of genetically identical clones on boulders around the tide line. Where two colonies meet they form a distinct boundary zone.
Anemones that contact an animal from another colony will fight, hitting each other with special tentacles that leave patches of stinging cells stuck to their opponent.
David Ayre of the University of Wollongong, Australia, and Rick Grosberg of the University of California-Davis previously studied individual anemone polyps' fighting strategies one-on-one.
Now they've been able to study two entire colonies as they clash.
The study shows very complex, sophisticated and coordinated behaviors can emerge at the level of the group, even when the group members are very simple organisms with nothing resembling a brain, Grosberg said.
The research was published in the journal Animal Behavior.
Copyright 2005 by United Press International
Explore further: Historical comet-landing site is looking for a name