Catch tentacles in the sea anemoneHaliplanella luciae

Abstract

Evidence is now gathering that indicates that the “catch tentacle” is an organ of social behavior in sea anemones, which attaches by nematocyst discharge to a feeding tentacle of a neighboring anemone. The typical adhesion response of catch tentacles was observed inHaliplanella luciae and further observations on such behavior were obtained. The active individual that had adhered the tip of an expanded catch tentacle to a neighboring species-mate did not act as a conqueror at all, but rather as a yielder, which would start to run away from the passive neighbor. The final effect on anemone distribution, however, was the same as in cases of aggressive contact in that segregation between individuals was thereby maintained. All individuals tested displayed catch tentacle development as would be predicted by the relative paucity of asexual reproduction in these populations.