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
Deep-water coral than tropical corals because there are no zooxanthellae to feed them. "Lophelia" has a linear polyp extension of about per year. By contrast, branching shallow-water corals, such as "Acropora", may exceed 10–20 cm/yr. Reef structure growth estimates are about per year. Scientists have also found "Lophelia" colonies on oil installations in the North Sea. Using coral age-dating methods, scientists have estimated that some living deep-water corals date back at least 10,000 years. Deep-water corals use nematocysts on their tentacles to stun prey. Deep-water corals feed on zooplankton, crustaceans and even krill. Coral can reproduce sexually or asexually. In asexual reproduction