The Crown-of-Thorns Starfish
The crown-of-thorns starfish, so named because of the spines that cover the upper surface of its body, is an integral part of coral ecosystems. These starfish help ensure the diversity of coral reefs by feeding especially on fast-growing corals. When they multiply beyond their usual numbers, however, they can consume entire populations of reef-building corals and severely disrupt the natural balance.
[Captions]
A group of crown-of-thorns starfish feeding on corals.
Reef-building corals before and after a starfish invasion.
The number of crown-of-thorns starfish exterminated around Ashizuri-Uwakai National Park by year.