Acropora reef-building coral synchronized sprawling

Full moon nights in summer are very special for corals. At 10 p.m., when water is around 24°C (75°F), Acropora digitifera corals in the southernmost part of Japan start to release their eggs and sperm, known as gametes, exactly at the same time in a process called synchronized spawning. (The coral which is shown here is Acropora.)