Occurrence of Two Endangered Fishes in the Little Snake River, Colorado

Abstract

Yampa River yet has been generally disregarded as potential habitat for endangered fishes. Wild, self-sustaining populations of endangered Colorado squawfish, Ptychocheilus lucius, and humpback chub, Gila cypha, occur in the Yampa River, but past surveys have not documented their occurrence in the Little Snake River (Holden, 1973). However, unconfirmed reports by local ranchers (Seethaler, 1978) and anglers suggested that Colorado squawfish and humpback chub use the river periodically. We report the first documented occurrence of Colorado squawfish and suspected humpback chub in the Little Snake River, Moffat Co., Colorado, during spring 1988. Information on Colorado squawfish use of the Little Snake River was gathered ancillary to investigations on winter habitat and spring migration of adult Colorado squawfish in the Yampa River. Observations of potentially suitable habitat for humpback chub and Colorado squawfish in the canyon section of the lower Little Snake River led to initiation of fish sampling. Collection of humpbacklike chubs of the Gila complex led to funding of studies to determine extent of use of the lower Little Snake River by endangered and other native fishes. Relative abundance of fishes collected during this investigation is reported.