Effects of Different Sources and Dietary Inclusion Levels of Astaxanthin on Growth Performance, Skin Pigmentation, and Physiological Parameters of Red Sea Bream (Pagrus major) Juveniles

Red seabream (Pagrus major) reared under intensive rearing conditions faces hypermelanosis and dyspigmentation, resulting in darker and less pink/red skin color, losing the natural appearance of the species. This has a great negative impact on consumers’ acceptance and market appeal. Two experiments were performed to test the effect of the source, level, and feeding duration of astaxanthin supplementation in the feed on red seabream skin color reversing the depigmentation problem. Firstly, three different sources of astaxanthin (artificially synthesized, algal-extracted, and yeast-extracted astaxanthin) at the same inclusion level (100 mg kg−1 feed) were tested. Then, the best performing source was tested using five inclusion levels (0, 20, 60, 80, and 100 mg kg−1) in the feed for 60 days. At the same time, growth performance, blood biochemical parameters, antioxidant capacity and cortisol levels were also assessed. The results showed that red seabream appearance can be significantly improved with the inclusion of astaxanthin from the algae Haematococcus pluvialis in the feed even at lower levels compared to the artificially synthesized astaxanthin for a 60-day period. Fish growth performance and blood parameters were not affected by any of the experimental treatments.