Arachidonic acid and α-linolenic acid, feeding attractants for the crown-of-thorns sea star Acanthaster planci, from the sea urchin Toxopneustes pileolus

In the tropical zones of the Indo-Pacific Oceans, the crown-of-thoms sea star Acanthaster planci, as the predator of corals, destroys coral reefs. We recently found that viscera of the sea urchin Toxopneustes pileolus produced a feeding attractant for this sea star. Using our simple bioassay system, we isolated arachidonic acid and alpha -linolenic acid as feeding attractants from T. pileolus. This is the first report about the sea star A. planci being attracted to unsaturated fatty acids. Interestingly, other unsaturated fatty acids such as eicosapentaenoic acid, docosahexaenoic acid and linoleic acid showed no activity. Our preliminary experiments indicated that these attractants have an attractive effect for the sea star both in the aquarium and in the sea. We anticipated that these attractants could be used to control A. planci. In addition, we verified the existence of arachidonic acid in the coral as one of the feeding attractants. (C) 2001 Elsevier Science B.V. All rights reserved.