Devil’s Hole Pupfish

North America


Cyprinodon diabolis


  • Limited habitat range
  • High sensitivity against any type of disturbance
  • Lowered water levels

The Devil’s Hole Pupfish is found exclusively within the underground water system in the Death Valley National Park, which is considered as the hottest, driest, and lowest natural park in the US.

This critically endangered freshwater fish species only has less than 40 remaining individuals, making it the rarest fish in the world. Among the pupfish species of the genus Cyprinodon, the Devil’s Hole Pupfish is considered as the smallest with only 30 mm (1.2 in) in length.

Scientists have no definite explanation but it is believed that the Devil’s Hole Pupfish cannot survive in any other habitat site – and that it is extremely sensitive to any type of alteration its environment – which is why the possibility for population growth is difficult. And for many factors that lead to the lowered water levels, this has also led to a serious decline in number.

Because of the shallow waters, the fish’ natural range is subject to an overabundance of silt and sediment, loss of prey species, as well as variations in the intensity and frequency of algal blooms. All of these can affect the breeding cycle and spawning capacity of the Devil’s Hole Pupfish.