Chemical defense through sensory disruption in spiny lobster-sea hare interactions

Meeting Abstract

P3.150  Friday, Jan. 6  Chemical defense through sensory disruption in spiny lobster-sea hare interactions LOVE-CHEZEM, T.*; AGGIO, J.; DERBY, C.; Georgia State University; Georgia State University; Georgia State University

Antipredator defenses are ubiquitous and diverse. The ink secretion of sea hares (Aplysia), consisting of ink and opaline, has been shown to be an antipredator defense acting on the chemical senses, as a decoy and repellent. It has also been hypothesized that the ink secretion, particularly the opaline component, may also act through sensory disruption. In this study, we test this hypothesis using the spiny lobster, Panulirus argus, as a predator. Opaline is a highly viscous substance, containing hundreds of millimolar concentrations of amino acids, which coats the antennules and mouthparts of attacking lobsters. This coating may contribute to a physical disruption of both chemical and mechanical sensing as well as contribute to chemical disruption by overstimulation of chemoreceptive neurons. Our experiments reproduce the coating of an antennule with opaline, components of opaline, and a mimic, which resembles its physical nature but lacks its chemicals. We used a food stimulus to understand the protective mechanisms behind this defensive secretion by measuring changes in motor activity associated with antennular movement, which occurs by chemical stimulation. We saw a significant decrease in this motor activity when opaline, the sticky component of opaline, or the mimic were applied to the antennule, but not when the amino acids from opaline or ASW were applied. This decrease suggests that opaline is a physical barrier against chemosensory input. We are currently completing electrophysiological recordings to understand how opaline affects the sensory cells in the antennules. Supported by NSF IOS-1036742

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