90-Day Finding on a Petition To List a Distinct Population Segment of the Roundtail Chub in the lower Colorado River Basin and To List the Headwater Chub as Endangered or Threatened With Critical Habitat

We, the U.S. Fish and Wildlife Service (Service), announce a 90-day finding on a petition to list a distinct population segment of the roundtail chub (Gila robusta) in the Lower Colorado River basin, and to list the headwater chub (G. nigra) as endangered or threatened under the Endangered Species Act of 1973, as amended (Act). We find that the petition presented substantial scientific and commercial data indicating that these listings may be warranted. Therefore, we are initiating a status review to determine if listing these species is warranted. To ensure that the status review is comprehensive, we are soliciting scientific and commercial information regarding these species. The petition also asked the Service to designate critical habitat for these species. The Act does not allow petitions for designation of critical habitat. However, any determinations on critical habitat will be made if and when a listing action is initiated for these species.