Invertebrates outnumber their vertebrate cousins many-fold on the reef. From shrimp and crabs, to colorful worms, to anemones, to clams, they come in an astonishing array of forms.
Corals come in a huge variety of forms and colors. There are hard (stony) corals that build the reef, and more delicate soft corals. There is such a diversity that even experts cannot decide on species boundaries for many types of corals.
Fish in Indonesia come in all colors, shapes, and sizes. The diversity of fish is literally unsurpassed anywhere else on Earth.