One of the rarest species on Earth, the Devils Hole pupfish, came close to extinction in recent months, thanks to an earthquake 500 miles from their deep desert cave. Now, worried scientists and divers are taking unprecedented steps to save the 38 remaining fish. … A few years ago, a mat was laid on the rock shelf of Devil’s Hole to collect pupfish eggs. Those eggs were then transferred to a replica of the cave built in nearby Ash Meadows Fish Conservation Facility. The fake Devil’s Hole contained the same 92-degree water and spawning shelf. There, in captivity, a backup colony of pupfish was bred. Nineteen of those captive fish were carefully brought into the cave in recent weeks.