The objective of this project is to understand the function, evolution, and neural mechanisms of chemical defenses used during predator-prey interactions. The project focuses on inking animals, using as experimental models sea hares and squid as inking prey, and fish and crustaceans as their predators. Experimental techniques used in this project include behavior, electrophysiology, analytical chemistry, and molecular biology. Inking animals use their ink as a visual smoke screen, mimic, or distractor, aiding them in escaping predators. But inking animals also use ink as a chemical defense, via diverse mechanisms. The first objective is to identify cellular mechanisms of chemical deterrence, by examining how chemical defenses of inking animals (sea hares, squid) affect the chemosensory systems of predatory fish (sea catfish) and crustaceans (spiny lobsters, blue crabs). The second objective is to examine how ink chemical defenses have evolved, by determining if the molecules in ink that act as chemical defenses have other functions such as serving as alarm cues or sun screens that predate their defensive function. The investigators expect to find a diversity of mechanisms of action, including some chemicals that activate specific deterrent receptor cells that evoke neural pathways evoking rejection, and other chemicals that inhibit food receptor cells and thus turn off pathways that evoke food search and acceptance. This work will contribute to the understanding of the predator-prey relationships, by showing how animals use limited resources to defend themselves against a variety of predators with diverse sensory capabilities and attack strategies. This work will also contribute to the understanding of principles of organization of chemosensory systems.
The project also has broader impacts, including: promoting training of students, especially underrepresented groups, in the practice scientific inquiry and creative thinking and writing; providing outreach and public dissemination of information; and commercializing antimicrobial technologies.
