Chemical Recognition and Nematocyte Excitation in a Sea Anemone

Abstract

The response of nematocytes in the anemone Stichodactyla haddoni to contact with complex organic compounds varies according to the 9ubstance concerned and in most cases according to the level of accompanying mechanical stimulation. Compounds with a proteinaceous moiety differ in their capacity to excite nematocytes, but usually tend to induce a stronger response than polysaccharides or lipids. Nematocyst discharge against foreign animals appears to be the result of a sophisticated cellular recognition process in which the nematocytes, and/or cells closely associated with them, respond to physical contact with a surface of appropriate chemical composition.