Abstract: This Small Grant for Exploratory Research (SGER) will support the rapid acquisition of DNA sequence for the Antarctic pteropod Limacina helicina, a resource that would allow the development of a cDNA microarray to profile gene expression in this critical marine invertebrate in response to ocean acidification. This request would facilitate the collaboration of the PI (Hofmann), a marine molecular ecologist, with co-PI, Prof. Victoria Fabry, an expert in pteropod calcification biology, and a leader in the ocean acidification research community. Finally, the resources developed here would be shared with the polar research community and all DNA sequence data and protocols would be available via web databases. Notably, the genomic tool developed here would most likely be useful for pteropods from Antarctic and Arctic waters. The broader impacts of this project would be the development of genomic tools for a critical Antarctic marine invertebrate that is threatened by ocean acidification. In addition, these resources would be shared with the polar biology research community.