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genetic variability. Given the high mtDNA diversity, it seems safe to assume that each individual is essentially unique; therefore, maximum diversity is achievable by maximizing the numbers of individuals used in the broodstock. It is important to note that we do not advocate selection for maximum variability of mtDNA or any other genetic marker, nor maintenance of unique markers or their specific frequencies. Nor do we wish to enter into the controversy of how much genetic variability is "enough." We simply recommend that the opportunity not be missed to preserve as much as possible of the existing genetic variation for this population (and species). The potential numbers of razorback suckers that can be cultured in a hatchery setting are spectacular, constituting a major temptation to managers assigned numerical goals for recovery. Using maximum values from DNFH Annual Reports (1982-198$), 100 females 45 cm SL could yield 1.43 X 106 ova. If survival to swim-up was 71.4%, 1.02 X 106 larvae would result. With 10% survival to a size of ±30 cm SL, 1.02 X 105 fish (nearly twice the estimated wild population) could be available for reintroduction in one reproductive season. Following this scenario, however, old, wild fish would die and be replaced by progeny from DNFH. Because of space limitations on broodstock numbers (potentially exacerbated by inbreeding), genetic variability will be dramatically reduced. Thus, while hatchery culture can be used to quickly produce large numbers of progeny, genetic variability will suffer. Even under ideal circumstances (e.g., ea~ualizing contributions of each individual to prevent adaptation to captive breeding; Allendorf, 1993), hatchery culture and stocking can maintain only a small proportion of the variability. This is because numbers of wild-caught broodfish required to maintain variability even approaching that indicated for Lake Mohave are clearly prohibitive. If conditions are not ideal, problems from unequal contribution of parents (as indicated by the 1990 year class), inadvertent~elecdon 25