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<br /> <br />' <br /> naturally. Once progeny have reached suitable size for release, they will be <br /> <br />' marked and released to the adjacent mainstem adult population. The amount of <br />genetic variability conserved by this technique is limited by the number of <br /> breeding adults, which in turn is limited by the acreage of available habitat. The <br />' same adults should not be used repeatedly for this purpose. <br /> 3. Utilize hatchery propagation based on a broodstock. Broodstock used in <br /> hatchery propagation should include the maximum number of wild fish possible. <br />' Strict breeding pedigrees should be followed to minimize inbreeding and at the <br /> same time pass on a maximum diversity of alleles to F2 progeny. Genetic <br /> variability passed on from a given-sized broodstock is governed by: <br />' a. measured contributions of gametes from individuals with known genetic <br /> attributes; or <br /> b. a statistical breeding regime based on the probabilities that each allele <br /> present in the broodstock is present in their progeny. <br />1 <br />1 <br /> <br />h <br /> <br /> <br /> <br /> <br /> <br /> <br />4. Use wild adults from Lake Mohave as broodstock. Once spawned, each wild <br />adult would be PIT tagged and returned to Lake Mohave, using each adult only <br />once. <br />Of these strategies, the first one is preferred as it maintains the highest genetic <br />variability in these fish by potentially using the maximum number of wild fish. <br />Regardless of the mating strategy applied, the only genetic variation that can be <br />passed on to the progeny in a hatchery setting is that of the original broodstock <br />(Minckley et al. 2003). If the complete component of genetic variance is not <br />captured in the broodstock, genetic variation will be diminished and less new <br />variation generated. The potential for reduced fitness due to fixation of <br />detrimental alleles may be increased. Such reductions in fitness when the <br />number of contributing individuals declines appear to be a particularly severe <br />problem in species with large ancestral populations and consequently high <br />historical genetic loads (Hedrick and Kalinowski 2000). Management to maintain <br />genetic variance should be under the most natural conditions possible, <br />emphasizing achievement and maintenance of the species' carrying capacities in <br />diverse habitats. The end result should be increasing opportunities for <br />emergence of novel variation, thus maximizing adaptive potentials. <br />CONDITIONING METHODS <br />12 <br />