In the night, the beach of Maldives turns to blue sea of stars, makes a matchless beautiful picture. What gives out fluorescence in dark night is a kind of lingulodinium polyedrum between animals and plants, whose size is only 1/20 millimeter. By day, they hide in the water, are uneasy to be seen, but in the night, when flapped by waves or stimulated, they will give up light as glowworms. Actually, the release of luminous energy is the means of defense for flagellates. The more severe they are stimulated, the brighter the blue light is.