Species interactions represent fundamental ecological processes that can have significant impacts on the evolutionary trajectories of species. However, the contribution of predator-prey interactions to genetic and phenotypic divergence within and between species remains largely unknown. In this context, predatory marine snails of the genus Conus exhibit considerable variation in venom composition, a phenomenon that may be due to the evolution of conotoxins in response to predator-prey interactions. It has been hypothesized that geographic differences in prey utilization drive the evolution of conotoxnis in cone snails and that the diversity of conotoxins is positively associated with prey diversity. To test if differences in predatory-prey interactions are associated with differences in venom composition, we sequenced and compared venom duct transcriptomes from 22 individuals of Conus miliaris from three geographic populations differing in dietary breath.