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averaged 75.1%. This was a substantial improvement over 1982 when egg viability was 30.5%. This is attributed largely to improved condition of the broodstock resulting in better quality sexual products, handling of eggs prior to incubation, and incu- bation temperature. Of 281,658 fry stocked, 159,367 advanced fry were harvested for a 56.6% return. We restocked 158,367 advanced fry and returned 136,419 three-inch fingerlings (86.1%); 53,845 of these were restocked to produce five-inch fingerlings and we got a 91.8% return (49,433 fish). We feed regular Service diet trout feed; conversion was 2.03. This year we stocked 2,539,548 fry, 82,487 three-inch and 43,433 five-inch fingerling razorback suckers in Arizona waters. All fingerling fish were marked with coded wire tags. Colorado Squawfish Like the razorback sucker, numbers of Colorado squawfish (Ptychocheilus lucius) have been reduced drastically throughout their historic range in the Colorado River basin. They are extinct in the lower basin and only a remnant population survives in the upper basin. North America's largest cyprinid, Colorado squawfish historically attained lengths up to six feet and weights of nearly 100 pounds (Miller, 1961). Because of a lack of mater- rial, it is not known how long Colorado squawfish survived histori- cally but all available data indicates that they are long lived. Nine-year-old squawfish reared in a hatchery environment average 20 inches in length and three pounds in weight. Knowing that razorback suckers live over 35 years it is not hard to speculate that a six-foot 100 pound Colorado squawfish would likely be at least 50 to 60 years old and probably older. Hatchery reared Colorado squawfish become sexually mature in their sixth year. Development of secondary sexual characteristics in Colorado squawfish are monitored weekly as water temperatures approach 650F in early May. Colorado squawfish at Dexter normally spawn