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1 <br />morphometric studies should be summarized as soon as possible and incorporated <br />into recovery management goals and reintroduction efforts. <br />I Historical distribution <br />Although several historical accounts describe bonytail throughout the <br />Colorado River system more than 100 years ago (e.g., USFWS 1990; Valdez and <br />Clemmer 1982), the basic biology of G. elegans was not studied in detail until <br />the late 1960's (Vanicek 1967; Vanicek and Kramer 1969; Holden and Stalnaker <br />1970; Vanicek et al. 1970). Early studies focused on the abundance, life <br />history, and distribution of native Colorado River fishes. During this <br />period, bonytail numbers were greatly reduced. Thus, the ecological <br />requirements of the bonytail remain poorly understood. Indeed, anecdotal data <br />on the bonytail were obtained from observations in artificial habitats such as <br />hatchery ponds or reservoirs. Furthermore, the vernacular use of the name <br />'bonytail' in the earliest records undermines factual references on <br />distribution (Banks 1964; Vanicek and Kramer 1969). Therefore the true <br />historical distribution of this species is unknown (Figure 1). The last known <br />concentration of bonytail was in Split Mountain Canyon of the Green River <br />through Dinosaur National Monument, Utah (Vanicek 1967). <br />Current status and trends <br />Very few fish have been captured and positively identified as bonytail <br />in the UCRB since 1980. Valdez (1985) identified 14 possible bonytail that <br />included juvenile and young-of-year fish in Cataract Canyon, Utah. Kaeding et <br />al. (1986) captured one bonytail from the Black Rocks section of the Colorado <br />River, Utah. Tyus et al. (1987) captured one bonytail in Gray Canyon. In <br />1993, a suspected adult bonytail was captured in the Colorado River about four <br /> <br />1