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. . . Egg production by females varied considerably, from 63,674 for hatchery-reared fish (Hamman 1985~ Jensen 1984) to 123,110 for wild fish (Jensen 1984). McAda and Wydoski (1980) estimated fecundity of wild fish at 24,490 - 76,576 eggs per fish. The eggs of razorback suckers have been incubated in a variety of ways and under a variety of temperatures (Table 2.6b). Inslee (1981) incubated eggs at 16.60C, while Minckley and Gustafson (1982) incubated eggs at 14 - 150C with hatching times of 5.3 - 5.5 days (127 - 132 hours). Eggs incubated at 210C (Jensen 1983b) hatched in 96 - 144 hours. Hamman (1985a) held eggs at 20 - 220C with 38.1 % hatching in Heath Trays and 54.7% in McDonald Jars. Swim-up fry were generally removed from the hatching trays or jars and held in small porous trays or containers during the 4 - 5 days of yolk-sac absorption (Table 2.6c). Approximately 4 days after hatching, and as the yolk sac was being absorbed and the mouth parts developing, the fry were transferred to larger holding units with feed. Inslee (1981) placed fry in 6-foot circular tanks lined with gravel and fed them a diet of trout starter four times a day (Table 2.6d). The fish were then transferred to 0.1 surface acre ponds and allowed to feed on natural zooplankton. Hamman (1987) transferred the fry to specially prepared and fertilized outdoor earthen ponds ranging in size from 0.34 to 1.08 surface acres, at a density of 101,000 - 109,000 fry per surface acre (71,OOOjlb). The fry fed on natural zooplankton in the pond at variable water temperatures of 9 - 2TC, with a survival rate of 87.8 - 98.6% after 69 - 78 days (Table 2.6d). At the end of Phase I, or with the fish 1.5 - 2.0 inches long, the fingerlings were transferred to earthen ponds 0.86 - 0.98 surface acres to feed on natural zooplankton supplemented with #1 and #2 granules of a commercial trout diet. At a stocking rate of 51,000 - 58,000 fish per surface acre (724 - 549jlb), survival was 92.7 - 95.8% after 51 - 70 days (Table 2.6e). Razorback suckers at Dexter NFH were often carried through a third rearing cycle (Phase III) in earthen ponds (Table 2.6f). 2.2 - 6