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Resources and Dexter NFHTC, unpub. data). More specific information on the reproductive
<br />biology of the Virgin River chub will be required in order to recover this species.
<br />Little information presently exists on movement of Virgin River chub. The Virgin and
<br />Muddy River populations do not mix even though the possibility exists through Lake Mead
<br />(Allan and Roden 1978). Downstream movemen within the Virgin River by adults and
<br />other life stages has been noted (Virgin River Fishes Data Base), but the extent of upstream
<br />movement, if any, is not known.
<br />Virgin Spinedace--The Virgin spinedace is endemic to the Virgin River drainage. The
<br />species was probably common-to-abundant in most tributaries and some mainstem reaches of
<br />the Virgin River above Pah Tempe Springs near Hurricane, Utah (Holden et al. 1974), but
<br />was probably less abundant in the mainstem Virgin River below Pah Tempe Springs. The
<br />current distribution of the Virgin spinedace has been greatly reduced from its historical
<br />distribution, and occurs almost exclusively in Utah. Current distribution includes reaches of
<br />the mainstem Virgin River, Beaver Dam Wash, the Santa Clara. River, Moody Wash,
<br />Mogatsu Creek, La Verkin Creek, Ash Creek, North Creek, Shunes Creek, and the lower
<br />reaches of the East Fork and North Fork of the Virgin River.
<br />The life history, food habits, movements, and reproductive biology of the Virgin spinedace
<br />were described by Rinne (1971), Deacon and Rebane (1989), Hardy et al. (1989), Deacon
<br />and Rebane (1990), and Rinne and Minckley (1991). However, much of the literature on the
<br />species documents taxonomy, distribution, and abundance. Principal taxonomy of the species
<br />was described by Tanner (1932, 1936), Miller (1952), Eddy (1957), Miller and Hubbs
<br />(1960), and Robins (1991). Distribution and abundance of the species is described by Tanner
<br />(1932), Miller and Hubbs (1960), Holden et al. (1974), Cross (1975), Valdez et al. (1991),
<br />and Hardy and Addley (1993). The following life history section summarizes current
<br />information concerning the species' habitat, food habits, reproductive biology, and movement
<br />based on this available literature.
<br />Life History
<br />The Virgin spinedace is usually found in clear, cool streams interspersed with pools, runs,
<br />and riffles. Rinne {I971) found that Virgin spinedace inhabited pools, often with undercut
<br />banks, debris, or boulders. However, heavily shaded pools, runs, and riffles were less
<br />frequently occupied. Deacon and Rebane (1989) reported that Virgin spinedace in the North
<br />Fork of the Virgin River used quiet pools most often; in Beaver Dam Wash they occupied
<br />narrow, shallow runs with large amounts of emergent vegetation and avoided the deeper
<br />pools. Both Deacon and Rebane (1989) and Hardy et al. (1989) observed that Virgin
<br />spinedace preferred the shear zone between high and low velocities with cover such as
<br />boulders, undercut banks, or vegetation. Hardy et al. (1989) and Deacon et al. (1991) found
<br />that spinedace were most often located in water depths of between 0.1 and 0.9 m (0.3 and
<br />3.0 ft) and velocities of 0.1 to 1.0 m/s (0.3 to 3.3 ft/s) with substrates of gravel and sand.
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