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culturing native southwestern fishes. Great strides have been made in documenting culture techniques for razorback sucker, Colorado squawfish, bonytail and humpback chub (Hamman 1981a, 1981b, 1982a, 1982b, 1985a, 1985b, in press; Inslee 1982; Jensen 1983, Jensen in Rinne et al. in press; Toney 1974) resulting in extensive hatchery production and reintroduction of several species, particularly razorback sucker. Brooks et al. (In prep.) have reported that introduced predators are a primary factor impacting the razorback sucker recovery effort and that this will likely be a continuing problem. This and other data accumulated in the first five years of this reintroduction effort indicate the need to modify current management techniques in order to further enhance recovery efforts for this unique catostomid. Reduction of predation by introduced catfishes might be accomplished by one or more management practices. Stocking larger fish (supposedly beyond predation size) and introducing them higher in the drainage system where fewer or no ictalurids occur would certainly enhance short term survival. This would at least allow ample time for stocked razorbacks to acclimate to the lotic environment prior to downstream dispersal. Perhaps after initial downstream movement, they might begin to "drop into" niches in the system and stay put. Not only do upper reaches of the drainage have fewer predators, but natural production of other native catostomids is extremely high, providing vast numbers of prey to offset predation on razorbacks by the predators that are present there. Stocking Salt River tributaries known to be free of introduced predators (both ictalurids and centrarchids) with 1.5" fingerlings (vs 10 mm swimup fry) may be successful. In 1985, 16 razorbacks (May stocking at 1.5") were recovered on 23 July (x TL = 3.3") both upstream and downstream of the introduction sites on Cedar and Carrizo creeks (FAIR, AZ); this following extensive flash flooding in that system from local thunderstorms. Other fish collected included Gila robusta, Catost:,mus insignis, Cstostomus (Pantosteus) clarki, Agosia chrysogaster and Rhinicht'~-•s osculus; no introduced fishes were collected. Direct removal or reduction of the predatory threat where it occurs, while practical to the successful reintroduction of razorback sucker, may not be acceptable to State game and fish agencies (AGFD in this case) or the sport fishing public (Brooks 1985). However, removal or depletion of predators by p~:::.;~HS or mechanical means from discrete sections of Che rivers relatively inaccessible to the angler could be accomplished without permanently or seriously impacting the sport fish populations. This would allow stocked razorback suckers an opportunity to acclimate to river conditions without immediate threat of predation. Winter stockings may also be desirable if colder temperatures reduce predator feeding activity (Brooks 1985). -44-