Meeting Abstract

78.1  Wednesday, Jan. 6  The Proboscis of Predatory Conus: Sensory Structures and Tissue Regeneration MARTIN, G.G.; JAMES, D.M.*; SCHULZ, J.; Occidental College, Los Angeles; Occidental College, Los Angeles; Occidental College, Los Angeles gmartin@oxy.edu

Over the last 50 million years members of the Genus Conus have evolved into over 600 species of predatory marine snails, many of which are highly specialized. Although there has been considerable interest in the pharmaceutical applications of Conus venom, there are relatively few studies on the morphology and comparative biology of the sensory structures within these marine gastropods. Three basic groups of cone snails have been proposed; vermivores, piscivores and molluscivores. All members of these three groups show a remarkable ability to locate and dispatch prey with powerful venom delivered by a radular harpoon found within the proboscis. With limited eyesight, reduced motility, and a nocturnal lifestyle, it is still unknown how they identify and locate their prey with such accuracy. Using SEM and TEM we have found ciliated structures (“sensory papillae”) near the distal tip of the proboscis from representatives of all three groups. Variations between these groups occur with the length, quantity, and position of the sensory papillae. Confocal and fluorescence microscopy shows extensive innervation within the proboscis leading up to the sensory papillae, suggesting that these structures do play a sensory role. Additional studies revealed that these sensory structures can regenerate after the tip of the proboscis has been ablated, which occurs in the wild as well as in lab settings. Feeding behaviors do not commence after ablation until the papillae have reformed. Further studies are needed to determine the type(s) of sensory information being detected by the papillae and if that is consistent among the three groups of cone snails.