Mummichog they swam normally. Fifty eggs at an advanced stage of development had also been taken on board, and 48 of them hatched during the flight. The hatchlings swam normally. More experiments with mummichogs in space followed as part of the Apollo-Soyuz Test Project and as part of a biological package aboard the Bion 3 satellite. Mummichog The mummichog ("Fundulus heteroclitus") is a small killifish found along the Atlantic coast of the United States and Canada. Also known as Atlantic killifish, mummies, gudgeons, and mud minnows, these fish inhabit brackish and coastal waters including estuaries and salt marshes. The species is
Mummichog most tolerant of salinity changes (euryhaline). Mummichog larvae can grow in salinities ranging from 0.4 to 100 parts per thousand, the latter being about three times the normal salinity of seawater. Adult mummichogs tolerate low oxygen levels down to 1 mg/L, at which they resort to aquatic surface respiration (breathing in the surface layer of water, richer in oxygen because of contact with air) to survive. They can even survive for a few hours in moist air outside of water, breathing air directly. Populations have developed resistance to methylmercury, kepone, dioxins, polychlorinated biphenyl, and polyaromatic hydrocarbons. One study has looked