The emperor penguins, the largest, are the only species that depend on the ice for breeding and rearing their chicks. Penguins feed on krill and fish. In turn, they are preyed upon by leopard seals and killer whales. Seals Four species of seals inhabit the Antarctic. Weddell seals feed on squid and fish.
Crabeater seals feed on krill .
They may be the largest group of all seals in the world and probably consume more krill than whales do. Crabeater seals are preyed upon by killer whales. Leopard seals prey on penguins and small seals as well as on krill , squid, and fish. Ross seals are seldom observed, very little is known about them. They feed mostly on squid and fish.