Both the initial and final astaxanthin concentration in the cutlets were different between the two fish groups, a finding that is also reflected in the colour card readings (Table 6). At the end of the experiment there were significant differences in astaxanthin levels in fish group I. Diets 1 and 2, which contained substantially less astaxanthin than the two other diets (Table 1), produced the highest astaxanthin levels in the cutlets of fish in group I (Table 6). The astaxanthin content in the cutlets of fish in group II was higher than that in fish group I, and there were no significant differences among the dietary treatments within group II.