Abstract:This study evaluated the effects of fish meal replacement with soy protein concentrate(SPC)on feed intake,growth and nutrient utilization of turbot,Scophthalmus maximus.Five experimental diets were formulated,in which FM protein was replaced by SPC at 0,12%,25%,37%(S75)and 49.5%,respectively.Five diets were supplemented with 0,0.83%,1.65%,2.48% and 3.30% essential amino acid mixture(L-lysine:DL-methionine:L-leucine:L-valine:L-threonine=18:6:3:2.5:2).Each diet was randomly assigned to triplicate groups of fish,and each group was stocked with 16 turbot [with an initial weight of (31.1±0.1)g] in 15 fiberglass tanks(300 L).Fish were fed twice daily(8:30 and 17:00)to visual satiation for 9 weeks.At the end of the growth experiment,feed intake(FI)(P<0.001)and specific growth rate(SGR)(P<0.001)decreased linearly with increasing dietary SPC levels.There were no significant differences(P>0.05)in feed efficiency ratio(FER)and protein efficiency ratio(PER)among fish fed diets with 0-37%SPC.Apparent digestibility coefficients of dry matter and crude protein of the diets were not significantly(P>0.05)affected by dietary treatments.These results indicate that protein from SPC could not effectively replace FM protein in diets of turbot because of lower feed intake.