Dolphins and beluga whales sleep by shutting down one hemisphere of their brain at a time. Because killer whales are physiologically similar to these species, it's thought that they sleep in the same way. While half of the killer whale's brain catches up on sleep, the other half controls the breathing.Aug 25, 2014
Killer whales are also known as orcas, a name that comes from their scientific name: Orcinus orca. ... Long ago, sailors referred to these massive creatures as "whale killers." Eventually that nickname changed to killer whale. In Spanish, they're referred to as ballena asesina, which means "assassin whale."