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<br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />(Haynes 1984), and adults that were apparently spawning have been noted <br />below the FWS site. This indicates that several sites in perhaps a <br />10-20 mile reach of the Yampa River are used for squawfish spawning. <br />The FWS has noted that several fish have been caught in the spawning <br />areas for 2-3 years, indicating an excellent homing instinct or fidelity <br />to a given site (Archer et al 1984). Movement of radio tagged adults <br />to and from the two spawning sites has also been well documented. <br />Therefore, spawning behavior of squawfi sh in the Green and Colorado <br />river systems is simil ar, but differences do ex ist. The fidel ity or <br />homing seen in the Green River fish is not seen in the Colorado River <br />and, therefore, well established spawning sites have not been documented <br />in the Colorado River. <br />The location of young (downstream) in rel ation to the suspected <br />spawning sites (upstream) has led to a drift theory for larval squawfish <br />(Tyus et al 1982). Young squawfish collected in the mid-1960's in the <br />upper Green River (Vanicek and Kramer 1969) do not support the drift <br />hypothesi s, suggest i ng that 1 arva 1 drift may be a recent accorrmodat ion <br />to some change in squawfish habitat, such as Flaming Gorge Dam. <br />Recent studies (Tyus et al 1982) have shown that adult Colorado <br />squawfish in the Green River migrate to spawning sites; migrations of <br />200 miles have been recorded. Squawfish move into the spawning areas in <br />1 ate June and Jul y, and spawn when temperatures have reached 200C for a <br />few days, which usually occurs when high runoff flows are receding and <br />the rivers are clearing up in late July and early August. They <br />apparently choose cl ean gravel bars to spawn on although actual egg <br />location has not been verified (Miller et al 1983). larvae are usually <br />found in late July or early August. <br /> <br />- 22 - <br />