704 



COX 



0000 



0600 1200 1800 



TIME OF DAY 



2400 



Fig. 1 Fluctuating acclimation temperature regimes for the first- 

 phase experiments indicating the times of day when critical thermal 

 maxima (CTMax) were determined. 



effects of cycling acclimation temperature is necessary for predicting 

 more accurately both the impact of entrainment-caused heat shock 

 and the consequences to fish of cold shock induced by power-plant 

 shutdown. 



MATERIALS AND METHODS 



In the initial phase of the experiment, a total of 270 young-of- 

 the-year striped bass, 6 to 7 g in weight and 8 to 9 cm in total length, 

 were randomly distributed among five circular tanks (1.2m in 

 diameter and 66 cm deep). Two of the tanks were maintained on a 

 computer-controlled fluctuating temperature regime with a 24-hr 

 period and a sinusoidal curve varying ±5°C around a 20° C base). The 

 temperatures in one tank rose between 0600 and 1800 hr, and, in the 

 other, temperatures fell between 0600 and 1800 hr — a time period 

 extending through the period of illumination (Fig. 1). Illumination 

 was provided by cool white florescent lights controlled by an outside 



