Biological sciences professor publishes pupfish research

Craig Stockwell, professor of biological sciences, has co-written a research article that evaluates the history of the Devil's Hole pupfish, which rapidly evolved following its isolation. The article published Sept. 17 in the Proceedings of The Royal Society B. 

The article, titled "Evaluating an icon of population persistence: the Devil's Hole pupfish," was co-written with J. Michael Reed of Tufts University.

The Devil's Hole pupfish live in one cavern-like habitat, a single pool found in the Mojave Desert in the southwestern United States. Their breeding range is only a few square meters, and they are considered one of the world's most vulnerable species.

"The pupfish are an iconic exception to the rule that small, isolated populations cannot persist. This species is thought to have been isolated since the Pleistocene epoch, 10,000 to 20,000 years ago. This short time span is very short for a species to have arisen, yet is very long for such a small population to persist. This assertion, however, has never been tested," Stockwell explained. "After analyzing population size and molecular data, we conclude that this species is unlikely to have been isolated for so long; perhaps for as little as a few hundred years."

The findings suggest Devils Hole pupfish diverged over a much shorter time span, and also suggest this species should not be used as a counter-example to the general rule that small populations have high vulnerability to extinction.  Earlier workers showed there was not a surface connection to Devils Hole, begging the question as to how pupfish colonized this habitat. Reed and Stockwell report instances in the literature that other pupfish species were used as an important food source for Native Americans who lived at nearby locations.

According to Stockwell, this suggests the possibility that people introduced pupfish to Devil's Hole.