Brown algae color is due to
Brown algae Phaeophyceae within stramenopiles display olive-brown hue due to dominance of accessory light harvesting carotenoid fucoxanthin over chlorophyll a, chlorophyll c1 and c2, and beta-carotene. Fucoxanthin bound to fucoxanthin-chlorophyll a/c protein complexes absorbs blue-green light 450 to 540 nanometers abundant at moderate depths, efficiently transferring excitation to chlorophyll a for photosynthesis. Pigment composition masks green chlorophyll, conferring characteristic coloration to kelps, rockweeds, and Sargassum. Unlike phycoerythrin providing red coloration in red algae and p
Ref: Lee Phycology 5th ed., Brown algae fucoxanthin; Campbell Biology 12th ed., Chapter 28 Stramenopiles brown algae pigments light harvesting
