Fauna
Species

Devils Hole Pupfish

Cyprinodon diabolis

Devils Hole pupfish carry out their entire life cycle in the upper reaches of a single geothermal cavern shelf in the Mojave Desert, surviving in constant 33°C (91°F) waters with exceptionally low dissolved oxygen. Adult males flare vivid iridescent blue flanks to defend tiny feeding territories on a sunlit rock ledge, while olive-yellow females deposit individual eggs in gravel crevices. Because the natural population fluctuates between a few dozen and a few hundred individuals, this desert relict stands as one of the rarest vertebrates on Earth.

Desert RelictEndemic
Devils Hole Pupfish reference1 / 3
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Critically EndangeredConservation statusIUCN Red List categoriesLCNTVUENCREWEXCritically EndangeredRed List categories, explained →
Key facts
Diet & preyFilamentous algae, Freshwater snails, Microscopic crustaceans
Predators
  • Predaceous diving beetle
  • Barn owl
  • Dragonfly nymph
ThreatsExtremely small range, groundwater depletion, genetic bottlenecks, and seismic disturbance
HabitatsGeothermal limestone cavern pool and shallow rock shelf
Life span10–14 months
Classification
  1. FamilyCyprinodontidae
  2. SpeciesCyprinodon diabolis
Range & activity
Range data is not available yet.
Safe observation
Interaction riskLow
  1. Low
  2. Moderate
  3. High
  4. Very high
Why interaction risk is low
Harmless to humans, but strictly protected from all direct contact or disturbance.
What to notice
Tiny, rounded desert fish lacking pelvic fins; breeding males shine metallic blue while females remain yellowish.
Support conservation
Strictly off-limits to unauthorized human access; view only from established observation decks.
Responsible observation
  • Viewing: Observe from the fenced visitor platform perched above the cavern fissure.
  • Binoculars: Bring spotting optics or a zoom lens, as the water surface is deep below the platform.
  • Site Etiquette: Never throw items or coins into the cavern opening, which threatens the fragile ecosystem.
Related species
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