Coral-killing starfish turns out to be four species, not one

The crown-of-thorns starfish, a notorious threat to coral in the Indian and Pacific Oceans, comprises four species, not one, biologists reported on Tuesday. The spiny predator, known by its Latin name of Acanthaster planci, has been a worsening peril to reefs for at least three decades, latching onto coral polyps and digesting them.