Examining the coral-reef ecosystems of tropical oceans, where brilliantly colored fish and other aquatic creatures find sanctuary. Included: how individual coral polyps form into huge reef systems; their remarkable spawning techniques; and predators that threaten them, including the bizarre crown-of-thorns starfish and a parrot fish that can bite through rock. Also: a colony of tiny shrimp that live within a sponge. Narrated by David Attenborough.
animal-behavior, exploration, ocean, sea-life