BURROWING BEHAVIOR OF THE SEA ANEMONE PHYLLACTIS

¹ Department of Biology, University of Arizona, Tucson, Arizona 85721

1. The burrowing behavior of the anemone Phyllactis is a very consistent and predictable activity.

2. Burrowing is accomplished by rhythmic contractions of the column musculature around a hydrostatic skeleton, with the result that fluid is alternately forced into and withdrawn from an inflatable pedal disc. This rhythmic activity forces the disc into the sand.

3. The interval between contractions is approximately 4 minutes at 21° C A pacemaker or set of pacemakers is postulated.

4. Under unusual conditions rhythmic movements may continue for hours. Normally, however, the anemone stops digging within 2 hours. After the pedal disc reaches a hard substratum and sand surrounds the column rhythmic activity ceases.