Studies were conducted to clarify the temperature preference and tolerance, and the effects of temperature on the growth of young Schlegel's black rockfish Sebastes schlegeli. A horizontal temperature gradient tank was used for the temperature preference test. The preferred temperature of the fish acclimated to 15-28°C ranged 17.8-22.8°C, with no clear dependence on the acclimation temperature. The final preferendum was estimated to be about 20.5°C. The upper and lower lethal temperatures of the fish exposed for 72h to eight or nine constant test temperatures ranged 28.1-30.5°C and 2.0-9.5°C, respectively. The critical thermal maximum and minimum ranged respectively 31.2-34.6°C and 1.3-4.9°C. The ultimate upper lethal temperature, which could not be exceeded with elevating acclimation temperature, was 30.8°C. In a rearing experiment, where the fish were fed Euphausia pacifica to satiation for 21 days at seven constant temperatures between 12 and 30°C, the highest daily feeding rate, daily growth rate and food conversion efficiency of the fish were found at 25°C, 22°C and 20°C, respectively.
The final preferendum was thus found close to the temperatures for the highest growth rate and food conversion efficiency.