Carotenoids inDaphnia

Abstract

Carotenoid pigments are found in the gut wall, fat cells and ovary ofDaphnia. A carotenoid-protein is sometimes present in the blood; the amount varies during an instar. The carotenoid-protein in the eggs ofDaphniaand certain other Cladocera undergoes a change when the embryos are fully developed. The protein link is broken and the freed carotenoid leaves the cytoplasm of the fat cells and intensifies the colour of the fat globules. Light promotes the deposition of carotenoids in the fat cells and eggs ofDaphnia magna. Females reared in the light contain three times as much carotenoid as similarly fed females reared in the dark. The carotenoid pigments ofD. magnahave been identified asβ-carotene,γ-carotene, lutein (esterified), and astaxanthin (part esterified). This is the first record ofγ-carotene in a crustacean.