Effects of Temperature on the Growth of Japanese Flounder

Abstract

Rearing experiments were carried out to examine the effects of temperature on the growth of Japanese flounder Paralichthys olivaceus at 10, 15, 20, 25, and 30°C with fish of about 4, 16, 88, and 176 g initial body weight. Fish were fed to satiation twice a day with a commercial pelleted diet for 20 days. In all body weight groups, the daily growth rates increased with temperature up to 20 or 25°C, though there was little difference in the rates between these temperatures. However, the rates decreased at 30°C. The daily feeding rates also increased with temperature up to 25°C, while the feed conversion efficiency decreased above 20°C. Therefore, the optimum temperature for the growth of Japanese flounder of the sizes tested is probably between 20 and 25°C. The daily growth rate at 30°C decreased more in larger flounder (88 and 176 g) than in smaller ones (4 and 16g), and the higher catabolic rate at 30°C for larger flounder appeared in the relationship between feeding rate and growth rate. Therefore, the high energy expenditure for catabolism appears to reduce the energy available for growth of larger flounder at 30°C. © 1994, The Japanese Society of Fisheries Science. All rights reserved.