SOUND PRODUCTION IN THE SPINY LOBSTER PANULIRUS ARGUS (LATREILLE) ,

1. The intricate stridulatory mechanism of the West Indian spiny lobster Panulirus argus, and the sounds it produces are described. The sounds are related to various patterns of behavior. 2. On the basis of behavioral evidence it is suggested that a slow rattle is characteristic of spiny lobsters when contained in groups, and that a rasp is a usual component of defensive behavior. 3. The characteristics of the sounds of P. argus are compared to those of other marine sounds of biological origin. On the basis of this comparison, an attempt is made to generalize(a) the type of sound which accompanies defensive behavior of marine fishes and crustaceans, and (b) the type of sound stemming from marine fishes and crustaceans when undisturbed. 4. It is concluded that the intricacy of the sound-producing mechanism of P. argus, and of other palinurids, justifies a conclusion of a significance of sound to the biology of spiny lobsters. While certain suggestions of a possible value of the rasp to survival of spiny lobsters are presented, a consistent effect of the rasp on the behavior of other spiny lobsters and on predator organisms has yet to be demonstrated.