Porposies eat mostly fish and squid.
Most whales eat fish, squid or crustaceans, diet varies depending on species.
The blue whale lives entirely on krill.
Dolphins are related to whales and porpoises.
Toothed whales (killer whales, dolphins, porpoises, narwhals, sperm whales, beluga whales) mostly feed on large fish.
Porpoises and dolphins are actually both toothed whales.
Orca Whales do eat penguins. The Orca diet also consists fish, squid, seals, sea lions, dolphins, porpoises, and large whales such as the Blue Whale.
Big fish do not eat seagulls. Although, whales and porpoises do, in fact, eat seagulls from the ocean surface.
Whales, Dolphins, and Porpoises, by Mark Carwardine.
Dolphins and porpoises are actually small whales and are related to whales.
A cetacea is a big marine animal with long ears and long snout,but strangely it has fur!
They have been known to eat Bottlenose Dolphins, porpoises, seals, minke whales, gray whales, sea lion, and seals.
The sperm whale (Physeter macrocephalus), is a whale.
Killer whales will eat ringed seals but they are technically whales in name only. They are more properly categorized in the same family with dolphins and porpoises. Baleen whales (like the blue whale) eat only plankton. Toothed whales (like the humpback) might eat a seal but are more likely going to stick to eating giant squid and the like.
Cetaceans (whales, dolphins, and porpoises) are carnivorous creatures. The toothed whales (including dolphins) feed mostly on fish and squid, although the orca (killer whale) often hunts seals, sharks, and other cetaceans. The giant baleen whales (Blue whale, grey whale, humpback whale, etc), on the other hand, specialize in eating tiny planktonic crustaceans called krill.