Meeting Abstract

S1-1.3  Friday, Jan. 4  The role of chemicals in interactions between inking molluscs and their predators DERBY, Charles; Georgia State University cderby@gsu.edu

Inking is a striking behavior of marine molluscs such as sea hares, octopus, squid, and cuttlefish. Inking can function as an antipredatory defense by acting as a visual smoke screen or visual decoy, especially in fast-moving cephalopods. But molluscs also use ink as a chemical defense. Ink of the slow-moving sea hares acts on the chemosensory systems of would-be predators such as crustaceans (spiny lobsters, blue crabs), fish (sharks, sea catfish, wrasses), and sea anemones through an impressive array of mechanisms. These include sensory inactivation (using chemicals in ink to disrupt the reception of appetitive chemicals naturally released by the would-be prey), deterrence (using aversive or unpalatable chemicals in the ink to deter the attack), and phagomimicry (using appetitive chemicals in ink to attract the predator to the ink and away from the releaser). Ink also functions as a chemical defense through alarm cues: sea hares show escape behavior when they detect ink from conspecifics. The chemical deterrents and alarm cues are diverse in molecular structure, numerous, and include both diet-derived and de novo synthesized molecules. Some alarm chemicals are multifunctional molecules, having been co-opted from other functions including as sun screens and antimicrobials. Fast-moving molluscs, such as squid, may also use ink as a chemical defense, since their ink contains chemicals that are unpalatable to predatory fish. Thus, using ink in both the chemical and visual realms may be a common defensive mechanism for inking animals. These modes of chemical defense contribute together with other defenses to protect inking animals from predators. Supported by NSF IOS-1036742