Orca

Orca/killer whales are the top of the food chain in the sea no animal prey on them exept for humans sharks are afraid of orcas there's a famous killer whale named keiko the whale from the free willy this orca died when he was set free. Killer whales are the largest dolphin family the male can reach up unto 32ft and the female is 26ft orcas bite force have'nt measured yet but there's a evidence that the killer whale's bite force is 19,000 PSI.

there'a answers to your questions

1.Are orcas dolphins?

The killer whale or orca (Orcinus orca) is a toothed whale belonging to the oceanic dolphin family, of which it is the largest member. Killer whales have a diverse diet, although individual populations often specialize in particular types of prey.

2.Do orcas attack sharks?

Killer whales (or orcas) are powerful predators capable of killing humans, leopard seals and great white sharks. They have also been recorded preying on usually terrestrial species such as moose swimming between islands. In the wild, there have been no fatal attacks and only one reported bite.

3.Do orcas sleep?

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.

4.What animal kills orca?

Some feed exclusively on fish, while others hunt marinemammals such as seals and other species of dolphin. They have been known to attack baleen whale calves, and even adult whales. Killer whales are apex predators, as no animal preys on them.