Most ubiquitous fish in western USA. Occurs in many isolated western drainages and has diversified tremendously. Treated as a complex of subspecies, but its morphological variations and distribution are poorly known. The following are protected as endangered subspecies: Rhinichthys osculus nevadensis in Ash Meadows, Nevada; Rhinichthys osculus oligoporus in Clover Valley, Nevada; Rhinichthys osculus lethoporus in Independence Valley, Nevada; and Rhinichthys osculus thermalis in Kendall Warm Springs, Wyoming. The Foskett speckled dace, Rhinichthys osculus subspecies, in Foskett Spring, Warner Basin, Oregon is also protected as threatened subspecies (Ref. 86798). Of some importance as forage species and widely used as bait fish. Also Ref. 5723.

Status of threat of the following subspecies: 1). Rhinichthys osculus lariversi: endangered. Criteria: 1,4,5; 2). Rhinichthys osculus lethoporus, Rhinichthys osculus nevadensis, and Rhinichthys osculus oligoporus: endangered; status same as 1989. Criteria: 1,4,5; 3). Rhinichthys osculus moapae: threatened; status same as 1989. Criteria: 1,3,4; 4). Rhinichthys osculus reliquus: extinct. Criteria: 1,4,5; 5). Rhinichthys osculus thermalis: endangered; status declined since 1989. Criteria: 3,5 ; 6). Rhinichthys osculus velifer: endangered. Criteria: 1,5 (http://fisc.er.usgs.gov/afs/) (Ref. 81264).