Neuromuscular Control of Directional Swimming in Cubomedusae

Cubozoan jellyfish (box jellyfish) include some of the most venomous animals in the ocean, and their habitat includes nearshore areas in use for human recreation. Recent evidence suggests that two less venomous species of cubomedusae are invading local North Carolina waters in large numbers, just off of popular beaches. Furthermore, these jellyfish belong to an animal group, including corals and anemones, with the simplest and most primitive multicellular nervous systems. Despite this simplicity, these animals have very rich behavioral repertoires and can successfully avoid obstacles, swim toward dim light sources, and respond to brief shadows. These properties underline the importance of understanding the neural control of behavior in this very active group of jellyfish: to better understand how to adapt human recreational activity to the expanding habitat of these venomous animals and to gain insight into the evolution of nervous system function, in general, related to behavioral variability and muscular control. As voracious predators on small fish and crustaceans, their impact on commercially valuable species has yet to be evaluated. Finally, information on the neural control of behavior in cubomedusae may be useful in animal-inspired marine robotics that may be of use in both commercial and military applications. This project will use a combination of electrical recording from neurons and muscles, structural examination of neuromuscular organization, and behavioral observations to describe the rapid and accurate turning abilities in response to both visual and mechanical stimuli, and to describe the strong swimming abilities of the jellyfish.