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. . . REFERENCE NUMBER: 013 CITATION: Colorado State University. 1989. ResearcJ1 hatchery squawfish propagation report. June, 1989. Unpublished report. Colorado State University Research HatcJ1ery. Fon Collins, Colorado. 3 pp. SPECIES AND LIFE STAGE: CS, CS_EGG, CS_LAR TOPICS: Production, Culture Techniques, Temperature, Diet KEYWORDS: COLORADO SQUAWFISH, EGGS, INCUBATION TEMPERATURES, FEEDS, BIOKYOWA. ZEIGLER LARVA SUMMARY: Colorado squawfish fry were subjected to different rearing treatments to determine dietary performance ot three feeds. Founeen hour old eggs from Dexter National Fish Hatchery were separated into incubation trays. Water was circulated through these trays at 227 lImin at temperatures ot 210C and 11.40C. Hatching began in the 210C trays after 80 h and was complete after 96 h. Since eggs were so small 3,600/ounce. no exact percentage ot hatching success couJd be obtained. The eggs in the 1l.40C trays 8disappeared8 after 12 days. Surviving fry were confined within troughs to small pans (158 x 128 X 58) with mesh tops and an aUstone in each to maintain high oxygen levels. These aUstones also kept food panicles suspended longer. FlSh were offered feed two days after hatching. Brine shrimp were fed to control groups at three temperatures (11.4, 15.5, and :zooq, Biokyowa was fed to three temperature groups and Zeigler (larva) and Rangen Trout diets were ted to two temperature groups (15.5, 2frC). Initially all treatment groups were fed brine shrimp twice daily and the test diet once daily. FISh other than control groups were then gradually switcJ1ed to the test feed three times daily. Observations in this repon are given prior to final completion. . Fry held at 1l.40C became vel}' lethargic after five days, quit feeding and suffered increased monallty rates. The remaining fish were condensed into one tray and the water temperature was increased to IS.5OC. After three days fish began eating again. Twelve days later water temperatures were lowered again and fish were still actively feeding and seemed healthy. It was determined that squawfish eggs cannot successfully be incubated at 11.40C, and swim-up fry cannot be Slaned on feed at that temperature. But after two weeks of initial feeding at a wanner temperature, fry can be switched to colder water and cultured effectively. Fish held at warmer temperatures (IS.5OC) were more active on Biokyowa dieL At 20"C all performance of fry on all feeds seemed equal. A-13