The rarest fish in the world is probably the Devils Hole Pupfish (Cyprinodon diabolis).
The source claimed that at last count, there was only a global population of about 75. (1)
It is only found in one place in the world.
A single limestone cavern is the home to the rarest fish in the world.
The cavern is in ‘Devils Hole’, which is a geothermal pool near the Death Valley National Park in Nevada.
The Devils Hole Pupfish also has the distinction of having the smallest geographic range as well. (2)
Rarest Fish in the World?
This beautiful iridescent blue fish is only about an inch long at full size. The endangered species has inhabited only the Devils Hole, for about 10,000 to 20,000 years.
The rare pupfish has a normal life span of just about one year. (3)
Research and conservation efforts are underway to try and save this small and rare fish species.
We hope that this has answered your question.