Killifish

Killifish (Fundulus spp.) are small fish tolerant of a wide range of temperatures and salinity, found throughout temperate and tropical waters on every continent except Australia and Antarctica. Not to be confused with the other large group of small fish in the same order (Cyprinodontiformes) known as minnows, killifish differ in having an incomplete lateral line, often not extending past the head, and a protruding lower jaw which allows them to feed from the surface. This characteristic gave rise to their other common name "top-minnow." Mummichogs (Fundulus heteroclitus) are the most well known species of killifish. Millions of these common intertidal fish have been removed from the East coast of North America since the 1800s for use in a wide variety of experiments, including a recent trip into outer space to determine the effect of weightlessness on fish development and locomotion.