Leaves also consist of such pigments as carotenoids, anthocyanins, and xanthophylls, giving rise to orange, red, and yellow colors. However, most of the year, we cannot see them under the dominant green chlorophyll. In autumn, a tree begins to dispose of the green pigment into nutrients (...
It converts the beta-carotene and xanthophylls it ingests into astaxanthin, a form of carotenoid, which is then stored in its exoskeleton, hence the crab appears bright red. Marine animals must constantly con- sume a source of carotenoids to main- tain their pigmentation, other- wise they ...