This project aims to determine the role of the nervous system and the impact of climate change on the complex patterns on snail shells. In many species the tissue that secretes new shell (mantle) is not in constant contact with the shell edge, requiring a snail somehow sense the existing pattern and transform that information into the appropriate next secretions to maintain the pattern. The stimuli to which mantle sensory neurons respond are not identified, nor the pathways by which sensory information is transformed to the next sequence element. This project will use the freshwater zebra nerite (Vittina natalensis) and local marine slipper snail (Crepidula fornicata) to investigate these issues. It will behaviorally probe what stimuli affect shell formation and pattern, with a focus on factors affected by climate-change. I will investigate the effects of temperature on growth by housing animals at the extremes and middle of their temperature range (Vittina, 18, 23, 28 degrees C, Crepidula 8, 16, 24 degrees C). I will also be housing some animals in conditions of different lighting (24 hr dark, 12:12, 24 hr light (preferably low-level light)). In animals housed in lit conditions, I will also examine the effect of visual environment by providing to different tanks white, striped, or spotted backgrounds. I will regularly examine the effects of these factors on growth rate and pattern elements (stripe width, angle of growth etc). Additionally, I will use staining to characterize the anatomical properties of candidate neural pathways involved in the pattern-continuation process, and electrophysiologically characterize the relevant mantle sensory neuron response properties. To do so I will require bench space for a dissection microscope and an air table for electrophysiological recordings. I am working with the Grass Fellowship coordinators on these aspects.