Sea surface temperatures have warmed by 0.5˚C within the last century and are predicted to rise 1-4˚C by the year 2100. These environmental changes become particularly concerning for ectothermic vertebrates, where metabolic rate is largely determined by environmental temperature. However, very little is known about how elevated temperature will affect the development of metabolically costly tissue, such as the nervous system. Elasmobranchs (sharks, skates and rays) occupy nearly every aquatic niche and play a key role in ecosystem structure and function. They also exhibit ontogenetic shifts, or changes in habitat, diet, or morphology, over the entire lifespan of an individual. Correspondingly, there are ontogenetic shifts in the relative development of sensory systems (e.g. visual, olfactory) and patterns of brain organization, potentially reflecting shifts in sensory specialization at key life history stages. However, to date, little is known about how normal development of the nervous system may be altered in response to an increase in environmental temperature. Using magnetic resonance imaging (MRI), this study compared the relative size of the eyes and olfactory rosettes in three representative species of cartilaginous fishes reared in ambient or elevated temperatures (3˚C – 5˚C): the little skate, Leucoraja erinacea, the port Jackson shark, Heterodontus portusjacksoni, and the epaulette shark, Hemiscyllium ocellatum. Trends indicate a difference in size of peripheral structures between treatment groups, which we hypothesize may reflect a decrease in metabolic efficiency at higher temperatures. Understanding effects of environmental temperature on the peripheral nervous system can have important implications for how changing ocean conditions may affect sensory capabilities, and thus longevity of these critical species.