About how many species of hard coral live on the Great Barrier Reef?

About 400 species of hard coral live on the Great Barrier Reef.

These reef-building corals belong to the order Scleractinia and produce calcium carbonate skeletons that accumulate over generations. Their colonies create the three-dimensional framework used by fish, molluscs, crustaceans and many other reef animals.

The number is an approximate count because taxonomists continue to revise coral identifications, and surveys may distinguish species differently. The reef’s coral diversity includes branching, massive, plate-like and encrusting forms, each suited to particular depths, currents and light conditions.

Hard corals are not the same as soft corals. Soft corals lack the rigid limestone framework that makes a reef, although they remain important parts of the wider Great Barrier Reef community.