The nature of the adhesion to shells of the symbiotic sea anemone calliactis tricolor (Leseur)

The mechanism of tentacular adhesion to gastropod shells has been demonstrated for a symbiotic sea anemone, Calliactis tricolor (Leseur) by means of scanning electron microscopy. Both basitrichous isorhiza nematocysts and spirocysts are involved with the former being much more abundant on the shells. Contrary to its classical characterization, the thread of the basitrichous isorhiza nematocyst possesses, in addition to the large spines at its base, minute spines along its length.