Desert Pupfish - JK

The Desert pupfish (Cyprinodon macularius) is an endangered rare species of bony fish found in only a few sites located in the United States and are usually found in shallow waters of desert springs, small streams, and marshes that are below 5,000 ft in elevation.

Their most notable attribute is their ability to survive in environments of extreme salinity, pH, temperature, and low oxygen content.

In terms of thermoregulation alone, those pupfish that live in the water flowing from desert hot springs have learnt to thermoregulate their body temperature extremely well all through the year by regulating where they are along the stream flow; from near boiling water when it first flows from the ground to cooling off as it flows away.

These pupfish forage around in shallow waters for food only during the early mornings and late evenings, and will move out of the shallow waters during the day when temperature rises to avoid heat death.