During which lunar phase do many coral species tend to spawn?

Many coral species synchronize their spawning events with the lunar cycle, particularly during the full moon phase. This timing is advantageous for several reasons. The full moon provides a brighter night sky, which may help the coral gametes—sperm and eggs—become more easily dispersed and increase the likelihood of successful fertilization. Additionally, the gravitational pull exerted during a full moon contributes to higher tides, aiding in the movement of water and the distribution of gametes across broader areas, thus enhancing reproductive success.

Spawning during the full moon also aligns with the behaviors of other marine species, creating a surge in reproduction in the ecosystem. Many marine organisms time their own reproductive cycles to coincide with coral spawning for similar reasons of increased chance of fertilization and survival. This synchrony showcases the intricate relationships within marine ecosystems and illustrates how environmental cues are essential for reproductive strategies in marine species.