Crown of Thorns | by Ocean Reality

Crown of Thorns starfish (Acanthaster planci) are voracious little predators. They preferable feed on stony corals, and when many of them come together, they can denude entire reefs of coral. Spiky and venomous, they have very few natural enemies. But these echinoderms fulfill a very important function in a reef-ecosystem: as they prefer to eat fast growing corals like Acropora, they create space for the slower growing ones. And that is great news for the diversity of a reef.

The guy filmed here seems to have gotten into a wrestling match with a sea-urchin. It probably has it’s reasons.