Devils Hole pupfish
A tiny fish found only in one cavern in Nevada.
The Devils Hole pupfish lives in a single water-filled cavern in Nevada. It is critically endangered and has been protected since 1967 due to its limited habitat.
- Lives only in Devils Hole, Nevada.
- Max length is thirty millimetres.
- Produces ethanol when lacking oxygen.
- Spawns after earthquakes disturb habitat.
- Critically endangered status since 2014.
What it is
This species is the smallest member of its genus, reaching just thirty millimetres in length. Males display metallic blue sides with black fin margins, while females are yellowish-brown. A key physical trait is the absence of pelvic fins, though they may grow them in captivity. The fish inhabits a deep limestone cavern where water remains at a steady thirty-three degrees Celsius. Oxygen levels are typically low, yet the fish survives through unique metabolic adaptations.
Where it lives
The entire global population exists within one specific location: Devils Hole in Nevada. This water-filled cavern sits in the Amargosa Desert ecosystem. The habitat covers a small surface area but extends over one hundred and thirty metres deep. Fish concentrate in the upper twenty-four metres, particularly on a shallow rock shelf that provides essential feeding and breeding grounds.
How it lives
These fish consume nearly every available resource, including algae, snails, beetles, and inorganic limestone particles. They exhibit paradoxical anaerobism, entering torpor to survive without oxygen for hours and producing ethanol as a byproduct. Predators include the predaceous diving beetle, which hunts eggs and juveniles. Seismic activity triggers mass spawning events as fish flee into deeper waters during earthquakes.
Breeding and life cycle
Reproduction occurs throughout the year, with peaks in spring and autumn. Females produce very few eggs, often only one per spawn, resulting in low survival rates to adulthood. The lifespan is short, lasting ten to fourteen months. Spawning can be induced by disturbances like earthquakes, causing males to chase receptive females until fertilization occurs.
Fish and people
Conservation efforts have been extensive and costly since the mid-twentieth century. Legal battles protected groundwater levels after agricultural irrigation threatened to lower the cavern's water table. Researchers maintain refugia populations and monitor wild numbers closely. Public opinion has been divided, with some arguing for extinction while others view preservation as vital.
Status and threats
The species is listed as critically endangered by the IUCN and was federally protected in 1967. Threats include groundwater depletion, seismic disturbances, and climate change. Population counts fluctuate significantly, dropping to dozens after winter earthquakes scour algae from spawning shelves. Conservationists remove sediment and install security measures to protect the fragile ecosystem.
Questions people ask about Devils Hole pupfish
Where does the Devils Hole pupfish live?
It lives exclusively in Devils Hole, a water-filled cavern in Nevada, United States. No other natural populations exist anywhere else in the world.
How big do Devils Hole pupfish get?
They are very small, with a maximum recorded length of thirty millimetres. The average adult measures around twenty-three millimetres long.
What do these fish eat?
They consume algae, snails, beetles, crustaceans, and inorganic limestone particles. Diet varies seasonally, but inorganic matter is eaten year-round.
Why is the Devils Hole pupfish endangered?
Its single habitat is vulnerable to groundwater depletion, earthquakes, and climate change. Low reproductive rates and small population size increase extinction risk.
Good reading and sources
- The Devils Hole Pupfish Just Can't Catch a BreakWired, Article
- Devils Hole Pupfish, Saved by Court in ’76, Is at Brink in ’08 (Published 2008)The New York Times, Article
- Devils Hole pupfish on WikipediaEncyclopedia
- More photos on Wikimedia CommonsPhotos
- Wikidata recordOpen data
The facts on this page come from the Wikipedia article "Devils Hole pupfish", written by its contributors and used under the CC BY-SA 4.0 licence, and from its Wikidata record (CC0). EveryFish rewrote the text in its own words, with AI assistance, and compares every page with the article to make sure no passage is copied. It may be reused under the same CC BY-SA 4.0 licence with a link back.
It may contain mistakes, and figures change over time. Nothing here is investment or buying advice. If something is wrong, tell us. Last refreshed 2026-11-15.
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