Abstract
Fundulus heteroclitus, more commonly known as the mummichog, is a species of brackish water killifish found along the Atlantic Coast of the United States and Canada. They inhabit mainly saltmarshes which experience large fluctuations in temperature, making this species exceptionally resilient to extreme environmental conditions and extremely well-adapted to their habitats. This study used pairs of sagittal otoliths to age fish from different populations in Maine and Massachusetts (MEMA) and Oyster Creek New Jersey (OCNJ) that experience differences in temperatures within their habitats. A statistical analysis was performed on the otoliths, correlating age with thermal tolerance to determine if it had a significant influence on the differences in thermal tolerance traits. Understanding what influences these differences in tolerances to environmental stressors could potentially provide new insight as to what traits will help fish to be able to survive the inevitable habitat changes due to climate change. Additionally, this study might provide new insight as to why these differences occur and may help in a larger understanding of species adaptations to a changing environment.