EVALUATION OF THE EFFECTS OF AN OXYGEN INJECTION SYSTEM ON THE GROWTH, HEMATOLOGY, AND IMMUNITY OF LAKE TROUT

Fingerling lake trout (Salvelinus namaycush) were reared for 64 d at t hree pressures of dissolved gases, expressed in relation to saturation values (DELTAP)-untreated (control) water, DELTAP = 10 mm Hg; water t reated by column degassing with air, DELTAP = 9 mm Hg; and water treat ed with an oxygen injection system, DELTAP = -20 mm Hg. Dissolved oxyg en concentration for experimental groups was increased with column deg assing by 7.8% and with oxygen injection by 8.7%. Nitrogen level was r educed 2.2% with columns receiving air and 7.4% with the oxygen inject ion system. There were no differences in production, mean lengths, or mean weights among fish reared in the three treatments. Hematocrit, pl asma protein levels, and mean antibody microtiters to injected Salmone lla H antigen were not different among fish from the three water treat ments.