A unicellular freshwater species of red algae known as "blood rain algae" is called Haematococcus Pluvialis. Blood rain algae are true masters of the art of survival, just like all other types of algae. They produce astaxanthin under external stress of shortage of water or temperature changes, which gives the algae and the water surrounding it their distinctive red color and gives them their name, thus aiding in the algae's ability to endure extended periods without food or water. The primary carotenoid found in the marine world of algae and aquatic creatures is astaxanthin, a member of the carotenoid family and a dark-red pigment soluble in lipids. When photosynthetic organisms absorb light, carotenoids play a supporting role as pigments. They oversee giving plants and algae their orange and red hues as well as giving aquatic animals a variety of blue, purple, and reddish hues. But only plants, algae, phytoplankton, certain bacteria, and fungus can synthesize carotenoids. As a result, all animals, including humans, must include carotenoids in their daily diet and rely on this outside source for their supply. The microalgae Haematococcus Pluvialis, which is the pigment's richest known natural source, is used to make astaxanthin. Recent research has demonstrated that this special carotenoid can shield proteins and crucial polyunsaturated fatty acids against lipid-membrane peroxidation. In skincare products, red algae are used to combat free radicals on the skin and shield the cells from cellular damage and early aging. They prevent skin thinning, encourage skin regeneration, and smooth the skin.