Endangered and Threatened Wildlife and Plants; Final Rule To List the Devils River Minnow as Threatened

We, the U.S. Fish and Wildlife Service, determine the Devils River minnow (Dionda diaboli) to be a threatened species under the authority of the Endangered Species Act of 1973, as amended (Act). The Devils River minnow is a small fish with a known distribution limited to three locations in Val Verde and Kinney counties, Texas, and one drainage in Coahuila, Mexico. The species' range is significantly reduced and fragmented due to habitat loss from dam construction, spring dewatering, and other stream modifications. The numbers of Devils River minnows collected during fish surveys over the past 25 years have declined; once one of the most abundant fish in the Devils River, the minnow has now become one of the least abundant. The species' decline in abundance in the Devils River may be attributed to the effects of both habitat modification and possibly predation by smallmouth bass (Micropterus dolomieu), an introduced game fish. We originally proposed to list the Devils River minnow as endangered. However, since publication of the proposed rule, a Conservation Agreement (Agreement) for the species has been signed and specific milestones for conservation actions have been agreed to by us, the Texas Parks and Wildlife Department (TPWD), and the City of Del Rio. We determine that the actions already accomplished under this Agreement, have reduced the imminence of the threats to the species sufficiently to justify a threatened designation. This action will implement Federal protection provided by the Act for the Devils River minnow. We determine that designation of critical habitat for the Devils River minnow is not prudent.