Venom Variation during Prey Capture and Development in Conus

Abstract

We investigate venom composition variation during both development and prey-capture in Conus species. Observations of the mollusk-hunter Conus textile during feeding reveal that prey are often injected multiple times in succession. Species that inject prey multiple times during a single feeding event may have compositional changes in their injected venom profiles. My work investigates the occurrence of venom composition changes after each injection and how these changes are related to the biomechanics of prey-capture. C. textile injected venom was collected from multiple shots in succession. Injected venom samples from multiple individuals were analyzed by mass spectrometry. We have found novel peptides not previously described from studies on dissected venom. Initial results support intraspecific venom variation as well as complex venom profiles that show compositional differences from shot to shot during a single feeding event. In addition to venom composition changes during feeding, we are also interested in compositional changes that may occur during development. Based on radular tooth morphology and gut contents, fish-hunting Conus begin post metamorphic life as worm-hunters. It is known in adult C. catus that vertebrate-targeted neuroexcitatory peptides are present in the injected venom. To address whether post-metamorphic juvenile C. catus express a distinct worm-targeted set of venom peptides lacking neuroexcitatory peptides, we have developed a systematic protocol to naturally induce spawning and rear C. catus larvae with the goal of raising larvae through metamorphosis. This is the first step towards studying venom compositional changes during development and opens the doors to sophisticated ontogenetic studies in this species.