Corals in the Great Barrier Reef spawn just once a year, a synchronised release of eggs and sperm under a full moon which produce young that go on to establish new coral colonies.
Now researchers at the Australian Institute of Marine Science filmed a coral doing just that in the National Sea Simulator, or SeaSim, near Townsville, Queensland.
Spawning is one method of coral reproduction, with different species doing so at different times to prevent hybrids being born. Corals on inshore reefs tend to start soon after the first full moon in October while those in outer reefs do so in November and December.
When an egg is fertilised, it develops into a larva. The larva floats in the ocean for a few days and eventually settles on the reef to begin a new colony – like the larva in the video above.