Ontogeny of the behavior of Strombus maculatus (gastropoda: Strombidae)

Abstract

The ontogeny of strombid behavior was studied by observing the behavior of Strombus maculatus veligers collected from the plankton and reared past metamorphosis to adults, and by observing juvenile strombids collected in the field. Complete adult modal action patterns (MAP's) associated with locomotion, feeding, and righting of overturned shells are performed by S. maculatus juveniles immediately after metamorphosis. There are changes in the frequency of the use of certain MAP's which are associated with variations in shell shape and size.The unique strombid escape response to molluscivorous gastropods (Conns spp.) is not released until juvenile S. maculatus are three weeks past metamorphosis and two millimeters in shell length. At that stage, the complete response is released upon the first encounter with a predator. Experience with a predator does not seem to lower the age or size criteria.During ontogeny there is a trend toward an increasing complexity of behavior which is paralleled by an increasing complexity of neural structure and general morphology. There are major steps in the ontogeny of strombid behavior which probably coincide with neural and morphological stages. © 1972 by the American Society of Zoologists.