Koh Hong's sand is actually fish excrement. Parrot fish and other coral reef munchers with fused teeth pulverize the exoskeletons of coral polyps as they graze like cows along the reef edge.
Koh Hong's sand is actually fish excrement. Parrot fish and other coral reef munchers with fused teeth pulverize the exoskeletons of coral polyps as they graze like cows along the reef edge.