In the 1970s, the discovery of the Tennessee snail darter in the Tellico River was used to halt completion of the Tellico Dam under the Endangered Species Act (a tale many law students learn in TVA v. Hill). The dam was only completed after Congress expressly exempted it from the ESA's dictates.
It has long been understood that the snail darter was the right species at the right time, as it gave dam opponents a powerful legal weapon. Now, the New York Times reports, it turns out the snail darter was not really the right species, as it is not a distinct species at all.
"There is, technically, no snail darter," said Thomas Near, curator of ichthyology at the Yale Peabody Museum.
Dr. Near, also a professor who leads a fish biology lab at Yale, and his colleagues report in the journal Current Biology that the snail darter, Percina tanasi, is neither a distinct species nor a subspecies. Rather, it is an eastern population of Percina uranidea, known also as the stargazing darter, which is not considered endangered.
Dr. Near contends that early researchers "squinted their eyes a bit" when describing the fish, because it represented a way to fight the Tennessee Valley Authority's plan to build the Tellico Dam on the Little Tennessee River, about 20 miles southwest of Knoxville.
"I feel it was the first and probably the most famous example of what I would call the 'conservation species concept,' where people are going to decide a species should be distinct because it will have a downstream conservation implication," Dr. Near said.
