Biochemical investigation of two responses involved in the feeding behaviour of Acanthaster planci (L). I. Assay methods and preliminary results

Material obtained by simple biochemical fractionation of aqueous extracts of coral has been tested for its ability to induce responses normally associated with feeding on live corals in the crown-of-thorns starfish, Acanthaster planci (L.) With the use of a new assay method, it has been shown that both dialysable and non-dialysable components of aqueous coral extract cause cessation of movement, settlement, and eversion of the stomach as if over a whole coral. A second response, apparently of avoidance, seen as a starfish approaches a coral prior to feeding, has also been examined; it is evoked by the dialysable fraction of coral extract.