Species Salvation: Saving the Owens Pupfish from Extinction
Edwin Philip Pister
Abstract.—The Owens Pupfish Cyprinodon radiosus is a small fish (<6 cm [2.5 in]) in the killifish family once thought extinct but rediscovered in the early 1960s in Fish Slough in the Death Valley drainage area of eastern California, USA. At the time of discovery, the species was comprised of a single population of approximately 200 individuals. The species was listed as endangered on March 11, 1967 under the U.S. Endangered Species Preservation Act of 1966. During the summer of 1969, a spring that was feeding water to Fish Slough was discovered to have much reduced flow due to unusual precipitation patterns the previous 6 months and possibly water removals, and thus threatened complete extinction of the species. Quick actions by fish biologists prevented extinction by transporting the entire species in two buckets to nearby refuge waters similar to Fish Slough. The transplantation was successful, and six populations now exist 50 years later that each number from the hundreds to perhaps more than 10,000 fish. The species remains listed as endangered—but it did not go extinct!