Submitted to: Aquaculture America Conference
Publication Type: Abstract Only
Publication Acceptance Date: August 5, 2003
Publication Date: March 4, 2004
Citation: Davis Jr, K.B. 2004. The effect of temperature on the stress response in sunshine bass [abstract]. In: Aquaculture America Conference. p. 51. Technical Abstract: Hybrid striped bass are thought to tolerate stress better than striped bass. Fish used in this study were produced at Keo Fish Farm, Keo, AR and were about 18 months old. Sunshine bass were subjected to a standard low-water confinement stress at temperatures ranging from 5 to 30 C. Stress was accomplished by lowering the water in the aquaria from about 60 liters to 5 liters with a short standpipe. Water volume was reduced in 5 minutes and remained at that level for 10 minutes. The water level was selected so that the fish were submerged, but were unable to maintain their posture in the tank. After 10 minutes the tall standpipe was replaced and the water level returned to the original 60 liters in about 45 minutes. Blood samples were taken at 0, 0.25, 1, 2, 6, 24 and 24 hours after the beginning of the experiment. Stress was evaluated by measuring blood hematocrit, plasma chloride, glucose and cortisol. Fish acclimated to 30 C had initial glucose concentrations below those found at 5 and 10 C. No other effects of acclimation were observed. Fish survived the conditions imposed at every temperature except 30 C, where 15 out of 42 fish died during the stress and recovery protocol. The general pattern was an initial increase in hematocrit, followed by a delayed decrease in hematocrit and chloride. Plasma glucose and cortisol increased in response to the stress and recovered to initial concentrations during the course of the experiment. In general, fish stressed at temperatures below 20 C temperatures had lower and more delayed changes in plasma glucose and cortisol than fish tested at 20, 25 and 30 C. Quantitative responses for glucose and cortisol were moderate and recovery was rapid in fish stressed at between 10 and 15 C, which was considered to be the best temperature to handling sunshine bass.