How Mummy and Daddy Corals Make Babies

Coral colonies have a mass spawning event every year. Polyps release tiny egg and sperm bundles into water all at the same time. Different species of coral release their eggs and sperm on different days to prevent hybrids from being produced. Once an egg is fertilised, it develops into coral lava - which I would love to call a baby. The planula floats around in the water for a few days before it settles on the ocean floor,. starts to grow, and a new colony develops. It's one of the coolest things about the Great Barrier Reef.