Effect of dietary protein level on growth and body composition of juvenile spotted sand bass, Paralabrax maculatofasciatus, fed practical diets

A preliminary feeding trial was made to determine the effect of dietary protein level on growth Ž . and body composition of juvenile spotted sand bass Paralabrax maculatofasciatus 9.5 g . Fish Ž . were randomly distributed in nine 600-l circular tanks 42 fishrtank , which were connected to a closed water recirculating system. Fish were fed practical diets for 93 days containing increasing Ž . Ž . protein levels 40%, 45%, and 50% . Significant lower weight P-0.05 was observed in fish fed Ž . the 40% protein diet 43.1 g compared to fish fed higher proteins diets. Growth rates, evaluated bX Ž . by an exponential model Ysae , and gross energy retention GER were significantly higher in Ž . fish fed the 45% and 50% protein diets than the fish fed the 40% diet P-0.05 . No significant difference among dietary protein levels was detected for the other growth variables measured, nor for the proximate composition of the whole fish, liver, or muscle. The use of a practical diet containing at least 45% protein is appropriate for growth of spotted sand bass juveniles. q 2001 Elsevier Science B.V. All rights reserved.