AbstractSix isonitrogenous and isoenergetic diets containing graded levels of lipid (menhaden fish oil) were fed to juvenile white crayfish (Procambarus acutus acutus) over a 10 week period. A significant depression in weight gain was observed in crayfish fed diets containing 9% or more lipid. There were no significant differences in growth of crayfish fed diets containing 0 to 6% lipid. Whole‐body percentages of lipid and dry matter decreased, and protein increased in crayfish fed high‐lipid diets. Dietary lipid did not appear to influence survival or molting frequency. Whole‐body lipids generally reflected dietary fatty acid compos