Influence of dietary lipids and culture density on rainbow trout ( Oncorhynchus mykiss ) flesh composition and quality parameter

•Combined effect of dietary lipid level and culture density on rainbow trout has been studied.•The negative effect of high densities on biometric parameter is offset by higher lipid intake.•Muscle fatty acid composition and firmness were affected mainly by the dietary lipid level.•High culture densities cause flesh darkening and lower pH and increases rigor development.