Astaxanthin is a pigmenting carotenoid occurring naturally in plankton, crustaceans and fish. The astaxanthin under assessment is of synthetic origin. The FEEDAP Panel considers synthetic astaxanthin safe for salmonids up to 100 mg/kg complete diet. The conclusion on the safety of astaxanthin for salmonids can be extrapolated to other fish and ornamental fish at the same dose. Dietary concentrations of up to 100 mg astaxanthin/kg feed are safe for crustaceans.