Apo Reef two lagoon systems, the north and south lagoons which are bounded by narrow reef platforms. It is a almost triangular northern and southern atoll-like reefs separated by a deep channel that is open to the west. The channel runs east to west from deep with a fine white sand bottom, numerous mounds and patches of branching corals under the deep blue water. The north lagoon is an enclosed triangular coral reef platform partly exposed during low tide. It is relatively shallow with depths of about . While the south lagoon is an inverted triangular coral platform enclosed on two sides
Coral reef fish too late. The clown triggerfish has strong jaws for crushing and eating sea urchins, crustaceans and hard-shell molluscs. Its ventral (lower) surface has large, white spots on a dark background, and its dorsal (upper) surface has black spots on yellow. This is a form of countershading: from below, the white spots look like the lighted surface of the water above; and from above, the fish blends more with the coral reef below. The brightly painted yellow mouth may deter potential predators. Many reef fish species have evolved different feeding strategies accompanied by specialized mouths, jaws and teeth particularly suited to