A Review of the Optimum Feeding Rates and Feeding Frequency in Korean Rockfish Sebastes schlegeli Reared at Seven Different Water Temperatures

Abstract

Seven feeding trials were conducted to determine the effects of feeding rate and frequency in the Korean rockfish S ebastes schlegeli at seven different water temperatures. Two feeding-rate experiments for 5-g Korean rockfish at 17 °C and 20°C; three feeding rate experiments for 16-g Korean rockfish at 16 °C and 24°C; and finally, two feeding frequency experiments for 93- and 100-g at 15°C and 20°C were conducted. Twenty fish averaging 5.5 ± 0.2 g (mean ± SD) were randomly distributed into 18 indoor tanks containing 40-L seawater from a semi-recirculation system. Fish were fed a commercial diet for 4 weeks at water temperatures of 17°C and 20°C. Two feeding trials were conducted to determine the optimum feeding frequency in growing Korean rockfish reared at temperatures of 15°C and 19°C. Broken line regression analysis of weight gain (WG) indicated that the optimum feeding rates of 5-g growing Korean rockfish were 4.48% (BW/day; BW, body weight) at 17 °C and 4.83% (BW/day) at 20°C. Broken line regression analysis of WG showed optimum feeding rates of 16-g juvenile Korean rockfish of 3.41% (BW/day) at 16 °C, 3.75% (BW/ day) at 20°C, and 3.34% (BW/day) at 24°C. The biological performance, results, along with morphological indices and serological characteristics, suggest that a feeding frequency of 1 meal/day was optimal to improve WG in growing Korean rockfish grown from 93 to 133 g at a water temperature of 15°C, and 100 to 132 g at 19°C.