Source of astaxanthin for fishes

Astaxanthin gives the shades of red we see in marine life like cooked shrimp, lobster and particularly salmon. Natural astaxanthin is delivered through feeding on migroalgae. Although astaxanthin itself appears as a red pigment, the light absorbency can be shifted to result in blue, green, yellow or brown colours when complexed with various proteins.

In marine environments, phytoplanktons are the primary producers of carotenoids. Phytoplanktons such as krill, are ingested by zooplankton or crustaceans and are prey for salmon and trout. The characteristic red carotenoid – astaxanthin – is then deposited into their flesh. Ornamental fish obtain carotenoids from feeding upon algae, coral or prey that have accumulated these pigments. Astaxanthin in either complexed or non-complexed form appear to be the most abundant carotenoids found in all marine animals. Carotenoids dominate in exoskeletons of crustaceans, coelenterata and many other marine species.