Whale sharks are gentle, filter-feeding giants, but orcas in Mexican waters were documented attacking the animals and devouring their livers.

For the first time, scientists have captured video evidence of orcas cooperatively hunting whale sharks, the largest species of fish on Earth. This graphic footage proves that whale sharks are a regular part of some orcas’ diets, and solves the mystery of how they are able to kill the massive fish.

Killer whales can feed on marine mammals, turtles, and fish. In the Gulf of California, a pod might have picked up new skills that help them hunt whale sharks—the world's largest fish, growing up to 18 meters long.

The method of hunting may imply that some orcas in the Gulf of California have acquired a special set of skills–like going after the ventral side of young whale sharks–that help them prey on these enormous fish. Orcas may have learned to do the same thing in other parts of the world, but evidence is limited, according to the team.