Threatened Species Status With Section 4(d) Rule for Longsolid and Round Hickorynut and Designation of Critical Habitat

We, the U.S. Fish and Wildlife Service (Service), determine threatened species status under the Endangered Species Act of 1973 (Act), as amended, for the longsolid (Fusconaia subrotunda) and round hickorynut (Obovaria subrotunda), freshwater mussels. We also designate critical habitat for both species. For the longsolid, in total, approximately 1,115 river miles (1,794 river kilometers) fall within 12 units of critical habitat in Pennsylvania, Kentucky, West Virginia, Virginia, Tennessee, and Alabama. For the round hickorynut, in total, approximately 921 river miles (1,482 river kilometers) fall within 14 units of critical habitat in Pennsylvania, Ohio, Indiana, Kentucky, West Virginia, Tennessee, Alabama, and Mississippi. We also finalize a rule under the authority of section 4(d) of the Act for both species that provides measures that are necessary and advisable to provide for the conservation of these species.