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<br />002826 <br /> <br />Background <br />Within the Upper Basin, stocking plans have been created for only the razorback sucker <br />in the Colorado/Gunnison rivers in Colorado (Burdick et a1. 1995) and in the middle Green <br />River in Utah (Wydoski 1996), and for the bony tail in the Green and Colorado rivers in Utah <br />(Lentsch et al, 1996), These plans were developed when the Recovery Program designated <br />razorback sucker and bonytail as priorities one and two, respectively, for .propagation and <br />stocking due to their extremely precarious status in the wild, Within Colorado in the Colorado <br />and Gunnison rivers, insufficient numbers of wild razorback sucker were available to use in a <br />5x5 breeding matrix to even attempt to develop broodstock. Additionally, the highest number <br />of razorback sucker remaining in Colorado, located in Etter's Pond near Palisade, Colorado, was <br />determined to be dominated by potential siblings from a very small number of parents, and <br />potentially hybridized with tlannelmouth sucker (Genetics Panel, Colorado River Recovery <br />Program, 1994). Therefore, mating crosses between two individual fish from Etter's' Pond was <br />determined to be genetically unacceptable due to inbreeding risks, The Recovery Program <br />approved development of a "blended stock" of razorback to serve as the broodstock for the <br />Colorado and Gunnison rivers, This stock was formed using razorback sucker from the <br />Colorado River arm of Lake Powell (4 fish), the San Juan arm of Lake Powell (4 fish), riverine <br />fish from the upper Colorado River (4 fish), and Etter Pond (3 fish). A captive spawning <br />strategy for these fish is described in Burdick et al' (1995) following the Recovery Program's <br />Genetics Management Guidelines (Williamson and Wydoski 1994). <br /> <br />Bonytail are represented by only one captive broodstock that is currently kept at Dexter <br />National Fish Hatchery in New Mexico, Some of these fish are also being held at Wahweap <br />State Fish Hatchery in Utah for reintroduction and broodstock development purposes, Since <br />these fish are the descendants from limited numbers of wild fish taken from Lake Mohave, and <br />no more viable adult bonytail are currently available from the wild stock remaining in Lake <br />Mohave, these fish represent the only genetic material left from which to base a propagation and <br />reintroduction program, <br /> <br />DRAFT - June 4, 1997 <br /> <br />2 <br />