Episode 1 Take me home
Photo courtesy of John N. Rinne

It may seem silly to consider fish desert animals when they are always in the water, but in fact, desert fish are often very special! Desert pupfish are some of the coolest little fish in the desert!

They are what some biologists call "living fossils" because they represent a group of animals that lived on the Earth many thousands of years ago. Keep reading for more information on this amazing Desert Survivor!
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PupfishPhoto courtesy of Nancy Hadlock

  • Pupfish can be found in many places throughout the country, but our desert pupfish are special because they live in such extreme environments.
  • There are about 30 species of pupfish in the American Southwest.
  • We are a type of spring fish, and many of the springs in the Mojave Desert have completely different species of pupfish that are all related!
  • Perhaps the COOLEST thing about the desert pupfish is they evolved from the same or a very similar ancestor. Thousands of years ago in the Pleistocene, the Mojave was a much wetter place. As the large lakes dried up, there were small springs and pools left behind where some water still seeped from the ground. Various organisms were trapped in these pools that continuously got smaller. The pupfish that were stuck in these pools were evolutionarily selected and became the species we recognize today. Now, though many of these small springs still have pupfish, they can be very different from pupfish in other springs. Some of these pools have species or subspecies that live no where else on Earth making them endemic!
  • Pupfish got their name because they seemed as playful as puppies.
  • Female pupfish are grey but males can be bright blue during breeding season.
  • Pupfish usually live 1 to 3 years.
  • Natural pupfish predators include birds and flatworms.
  • Introduced pupfish predators include bullfrogs and crayfish.
  • Pupfish can be found along the Atlantic, Gulf of Mexico, and Caribbean coastlines. They are also found scattered throughout deserts in northern Mexico and the southwestern U.S.
  • Pupfish live in temperature ranges from 0 to nearly 100°C (32°F to 212°F).
  • Pupfish can live in water 3 times as salty as the ocean.
  • The lifecycle of the pupfish depends on food availability.
  • Pupfish have been around since the late Pleistocene, about 20,000 years ago!
  • Several species of pupfish are endangered.
  • Pupfish are famous! They were the first animal to be reviewed in the Supreme Court of the United States!
  • They have made local and national news!

Size: We're about 5 cm (2 inches) long. About the size of your average pet goldfish.

Color: We can vary a lot in color, but generally we are grey, with the males being more blue in mating season.

Pupfish are found along the Atlantic, Gulf of Mexico, and Caribbean coastlines. We are also found in the southwestern U.S.

Pupfish survive by tolerating environmental extremes of temperature and salinity. Our water can be so cold it has ice in it (0°C) and nearly so hot it almost boils (close to 100°C)! We can also survive water that's three times the salinity of the ocean!!!

Pupfish distribution

The Mojave Desert has a very special group of pupfish that is collectively called the desert pupfish. We are possibly the most exciting group of pupfish because our environment is so unusual! Desert pupfish are found all over the Mojave Desert.

Salt Creek and Saratoga Springs of Death Valley, along with Ash Meadows (outlined by the red box in the picture to the right) of the Amargosa Valley, just west of Pahrump, are the locations with some of the largest populations of desert pupfish.

Ash Meadows has a surprising number of springs and pools that host many species and subspecies of pupfish! Devil's Hole is one of these small, but very special aquatic habitats.

Pupfish rangePhoto courtesy of Nancy Hadlock

Devil's Hole is a rock pool about seven by three meters (22.6 feet by 9.8 feet), imbedded 15 meters (48.8 feet) down in the solid rock surroundings. Although the pool is small, it is the opening to a very deep (we don't know how deep, it is at lease 60 meters or 200 feet) and only partially explored underground reservoir.

Once called the Miner's Bathtub, it has come to be known as "Devil's Hole". It serves as home to the small, rare, Devil's Hole pupfish (Cyprinodon diabolis) which has been surviving the extremes of desert life for over 20,000 years! Though each individual only lives a few months to a year, this population has seen many climatic changes and has managed to stay on the map as one of the desert's most facinating Survivors.

Devil's Hole
In fact, without the transition from a more moist climate of the Pleistocene era to the arid desert climate of the present, the Devil's Hole pupfish may never have been that fascinating at all! Scientists believe the isolation of the Devil's Hole pupfish through geological and climatic changes and the great genetic variability of the fish contributed to the pupfishs' survival and evolution into what you see today.

We eat algae and small invertebrates (animals that don't have backbones). Check out how closely our lifecycle follows the trends in food availability!!!

We are often dinner to other animals like birds and flatworms, but these animals rarely eat enough of us to impact our population numbers too much.

We do, however, have predators that have significantly lowered our population numbers recently. Introduced species like the bullfrog and crayfish eat large numbers of us, particularly our young. Rangers and biologists are always working to keep introduced species at bay.

The lifecycle of the pupfish centers around food availability. Pupfish spend their entire lives in small springs where they mate, lay eggs, hatch, mature to adulthood, and begin the cycle again. They usually live a few months to a year, some have been known to live as long as 3 years.
Pupfish lifecycle

Because desert pupfish are becoming so scarce, most of the research done on them centers around conservation. Scientists are working to increase population numbers and keep the different species isolated to prevent hybridization.

Here a diver investigates the caverns of Devil's Hole. Scientists have been working in Devil's Hole for decades, and the extent of the underwater features is still no where near clear!


nearly a toadlet adult toad toadlets

1. What is our most famous pupfish? The Devil's Hole Pupfish.

2. Why are pupfish so special? They have been surviving the extremes of the desert for thousands of years by hiding out in the small remaining springs and ponds of the Pleistocene era.

3. What is the pupfish's lifecycle based on? Food availability.

4. If you could be any aquatic animal, what would you be an why?

Dr. Jim Deacon Soon after completeing his PhD at the University of Kansas, Dr. James Deacon took a job as the second Biology professor at the little known University of Nevada, Southern. He traveled to Las Vegas, school and city unseen, to start research on an organism he had only read of in books! Only after forty years of service in research and teaching did he retire in 2002, from the same university, though it had transitioned to the large campus of what is now UNLV!
After nearly a half century of research and study, he has achieved recognition as the world's expert on desert pupfish. Dr. Jim still visits the campus daily and is a well respected and loved member of the campus communitee. He and his daughter continue to write ecologically relavant literature regarding desert pupfish.

Nancy Hadlock

Nancy Hadlock is an educational specialist for the National Parks Service. She is currently heading the community educational outreach and interpretive programs at Ash Meadows. She encourages teachers, and school kids especially, to get involved in programs at Ash Meadows.

"No group is too small," Hadlock said. She can be contacted at the wildlife refuge station: (775) 372-5435.

Tune in to Episode Four to find out more about what makes these desert organisms so special! Episode Four highlights desert pupfish, Ash Meadows and human impact on the environment.
Desert USA - for informatin on over 60 desert organisms!
The Most Endangered Pupfish - Lots of info about the Devil's Hole pupfish
Ash Meadows National Wildlife Refuge - Info about where to see pupfish
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