Story of how fish got stuck in the desert was possibly oversimplified
The alarmingly rare Devils Hole pupfish — known from only one pool in a Nevada desert —might not be the long-isolated species it has seemed.
The small, bluish Cyprinodon diabolis fish inhabits Devils Hole, a collapsed cavern filled with water in the Mojave Desert. To explain how fish got into such hostile terrain, biologists have speculated that C. diabolis and some related local pupfishes in the area descend from residents of ancient bodies of water that disappeared from the region more than 10,000 years ago. As those waters receded, fishes took refuge where they could, the idea goes. By now, descendants have adapted to odd remnant habitats of wetter days.
That intuitively appealing story, however, does not fit with hints from new genetic evidence, says Christopher Martin of the University of North Carolina at Chapel Hill. The Devils Hole pupfish appears to have recently shared genes with desert pupfishes that live in springs or