Comparison of Growth, Feed Efficiency, and Chemical Composition of Juvenile Flounder Fed Live Mysids and Formula Feed under Laboratory Conditions

Abstract

The objectives of this study is to compare growth, feed efficiency, and chemical composition of juvenile flounder Paralichthys olivaceus fed live mysids and formula feed under laboratory conditions. Four rearing experiments (9 to 10 days), using four different size fish, were conducted at four different constant temperatures (13, 16, 19, and 22°C). Temperatures used in the present study were chosen according to those at the nursery ground in Wakasa Bay during spring and early summer. Fish were fed live mysids or formula feed during experiments. Fish fed live mysids showed always higher growth rates in length (1.04-2.09 times in expts. 1-4) and weight (1.14-2.65 times in expts. 3 and 4), better feed efficiency (1.56-4.34 times in expts. 3 and 4) than those fed formula feed at any temperatures. Chemical compositions (proximate composition and fatty acid profile) of fish at the end of experiments reflected those of diets, and those of fish fed live mysids were nearly the same as those of wild juveniles.