In the late-1970s, a small freshwater fish known as the snail darter made history when its newly acquired status as an endangered species helped to temporarily block construction of the Tellico Dam in Tennessee — a David versus Goliath victory in what was the first legal test of the U.S. Endangered Species Act (ESA). 

A new study by Yale researchers shows that the tiny fish, discovered in a lower stretch of the Little Tennessee River in 1973, is not a distinct species at all, meaning it was never endangered. 

The researchers, who combined analyses of genetic data and the fish’s physical structures, found that the snail darter is actually a subpopulation of a species known as the stargazing darter, a ray-finned species first described in 1887.

The discovery demonstrates the ability of modern analytic techniques to help scientists delineate species and identify those that do face endangerment — information that can support efforts to protect the planet’s biodiversity, said Thomas J. Near, professor of evolutionary biology in Yale’s Faculty of Arts and Sciences, YIBS faculty affiliate, and senior author of the study.

“While we’re losing the snail darter as a biological conservation icon, our findings demonstrate the capability of genomics, in addition to studying an organism’s observable features, to accurately delimit species,” said Near, who also is the Bingham Oceanographic Curator of Ichthyology at the Yale Peabody Museum. “Through the combination of these methods, scientists today are more empowered than ever to identify endangered species — discoveries that can help guide future conservation decisions.”   

He added: “The bottom line here is that we want the science used in defense of conservation to be good science.”

For more information, click here for an article published by Yale News or here for an article published by The New York Times.