The desert pupfish is a fish - that lives in the desert! They are found in pools, streams, lakes, marshes and springs in southern Arizona and California. These playful cousins of the guppy also have amazing adaptations allowing them to survive extreme temperatures at more than 110° F, and excessively salty water - more than twice as salty as the ocean. These tiny 2-3 inch fish are energetic and frolicking, like the puppies they were named for.
During the spring and summer, female desert pupfish will find a colorful blue and yellow male and lay one egg for them to fertilize and guard. She will lay more than 800 eggs. Once they hatch, they are on their own, hiding from predators in algae and undercover. They will most likely live one year but can live up to three. Desert pupfish eat algae, snails, larvae, aquatic insects, and occasionally their own frye(young pupfish) and eggs. Desert pupfish also help keep the mosquito populations down.
A male pupfish with a yellow tail and blue body. Image courtesy of the Center for Biological Diversity.
The desert pupfish is able to survive in intense conditions because they can withstand a wide range of temperatures, from 110° F to 40° F. When it gets colder in the winter, they will become dormant after burrowing in the mud until the waters warm up. They can also withstand low amounts oxygen and quick fluctuations in temperature up to 8°. These amazing desert pupfish can survive in waters most fish would not be able to!
Despite the desert pupfish’s hardiness, they are not indestructible and due to several reasons are now listed as endangered under the Endangered Species Act. One reason for this is human diversions of the water, which messes up the pupfish’s habitat. Agriculture and livestock also grazing release pesticides in the water and competition from invasive species such as tilapia and mosquito fish reduce the pupfish's ability to feed and reproduce as well as bring disease and habitat displacement. Although the amount of places where the pupfish currently resides has fragmented, due to conservation efforts they have many stable and increasing populations found in refuges or places where other fish can’t survive.
Desert pupfish (Cyprinodon macularis). (n.d.). Retrieved May 01, 2021, from https://wildlife.ca.gov/Regions/6/Desert-Fishes/Desert-Pupfish
(n.d.). Retrieved May 01, 2021, from https://www.biologicaldiversity.org/species/fish/desert_pupfish/index.html
Desert pupfish. (n.d.). Retrieved May 01, 2021, from https://www.phoenixzoo.org/local-conservation/desert-pupfish/
Cover image courtesy of California Department of Fish and Wildlife.