Only once a year, and lasting just a few minutes, the mass coral spawning is one of the most spectacular and mysterious phenomenon underwater – where many colonies of coral simultaneously release their eggs and sperm into the ocean for external fertilization. These gametes rise slowly to the ocean surface, where the process of fertilization will begin. The underwater “snowstorm” makes the fertilization more likely to occur since the gametes released by mature corals are viable for only a few hours. Though it is still difficult for the scientists to predict the exact timing of the annual synchronized spawning event, it is known that the phenomenon usually occurs over several days after a full moon, and which only happens at night with rising water temperatures stimulating the maturation of gametes within the polyps. Photo taken in Kenting, Taiwan.