Activation of Defense Mechanisms in the Nudibranchs Peltodoris nobilis and Hermissenda crassicornis

Nudibranchs are marine invertebrates that use various defenses to deter predators. Peltodoris nobilis is a member of the superfamily Doridoidea and uses de novo chemical synthesis for defense. Hermissenda crassicornis Aeolidioidea nematocyst sequestration Past research explains function evolution in nudibranchs; however, it unknown whether these active or passive. The goal this was determine if defense mechanisms P. H. passive one method more effective at preventing predation than other. It hypothesized activation both nudibranch species were equally predation. This hypothesis tested by comparing contact times juvenile Glebocarcinus oregonensis crab— predator nudibranchs—with an anesthetized non-anesthetized nudibranch. There no statistical difference crab between control with crabs statistically higher control. suggests release chemicals produced passive, while firing sequestered active. results also indicated lower those nobilis; demonstrated little predatory behavior across all trials. Therefore, study cannot conclusively which mechanism