The mummichog, Fundulus heteroclitus, is a small killifish found in the eastern United States. Also known as mummies, gudgeons, and mud minnows, these fish are found in brackish and coastal waters including estuaries and salt marshes along the eastern seaboard of the United States as well as the Atlantic coast of Canada. It is noted for its hardiness and ability to tolerate highly variable salinity, temperature fluctuations from 6 °C to 35 °C (43 °F to 95 °F), and for...