Abstract

The behavior of the ragged sea hare, Bursatella leachii pleii Rang, was observed in its natural habitat and in captivity. An indication of the seasonal availability of Bursatella in Puerto Rico was obtained by making multiple observations at a single site. The behavior patterns of Bursatella in the field were indicative of a daily rhythm. They tended to be found in groups at sunrise and as isolated individuals in the afternoon. They were observed to assemble following sunset and to disperse in the morning. Certain aspects of this rhythmic pattern of behavior persisted in animals held in the laboratory, where copulation was the most common behavior in the morning and feeding-related activities became more prevalent in the afternoon. Specific behaviors related to autonomic function (respiration and digestion) were also observed and quantified. It is proposed that the rich behavioral repertoire exhibited by B. leachii, and the ease with which these animals are observed in their native habitat, provide favorable systems for studying neuronal mechanisms involved in the organization and evolution of complex behavior.