Polysiphonia Red Algae

While there are more than 4,000 catalogued species of red algae worldwide, most are found in tropical marine waters, and only a few are freshwater species. Polysiphonia, a common genus of marine red algae, is red in color because of the pigment phycobilin, which masks the green color of the chlorophyll responsible for photosynthesis. As a red-colored plant, Polysiphonia is well suited to absorb the green and blue-green light that typically penetrates the deeper sea water where these red algae thrive.