UCB Moorea Class: Biology and Geomorphology of Tropical Islands

The defensive behaviors of four opisthobranchs (Glossodoris cincta, Risbecia imperials, Stylochelius striatus, and Dolabrifera dolabrifera) were observed and categorized. The displays studied were mantle flexation, mucus production, mantle secretion, inking, and rearing. Members of each species were placed in two laboratory situations containing two different antagonists. The antagonists (Dardanus lagopodes and Lutjanus fulvus) were chosen because they were carnivorous, abundant, and found in the same ecology as the opisthobranchs studied. Additionally, they were chosen because they differed phylogenetically, physiologically, and behaviorally and, therefore, represented two very different predators. In some cases, individuals exhibited different defensive behaviors in the presence of different antagonists. Differential responses could reflect physiological, biological, or phylogenetic differences between the four observed opisthobranch species. In some instances, defensive displays were observed across lineages.