ABSTRACT
Astaxanthin (3,3'-dihydroxy-P,P-carotene-4,4'-dione) was first described in aquatic crustaceans as an oxidized form of @-carotene, which gives the marine invertebrates (lobsters, crabs and shrimps) and fish (salmon and trout) the distinctive orange-red colour (Johnson and An, 1991). It was later found that the red pigment is a widely distributed carotenoid in the animal kingdom, especially in marine animals. However, only few animals can synthesize it de novo from other carotenoids and most of them acquire it in their food.
