The machines viciously retaliate by falling on and crushing their tormentors. Whitetip reef shark cruises past crown-of-thorns starfish. NOVA: Do sharks have enemies? Gruber: The greatest enemy of ...

A new study suggests that the removal of predatory fish such as sharks from coral reefs may be a key factor driving outbreaks of coral-eating crown-of-thorns starfish. Dr. Mark Meekan and Dr.

One is a colossal apex predator, feared and respected across the seas. The other, a sleek and stealthy hunter, lurking in coastal waters. When it comes to the great white shark and the spotted gully ...