The smallest whale, the dwarf sperm whale, can eat up to 2,204 pounds of food a day. The largest whale, the blue whale, can eat 8,000 to 16,000 pounds of food a day.
Blue whales have no teeth. They filter their food out of the water using long, thin plates of keratin known as baleen plates. Blue whales eat krill and copepods, which are very small crustaceans. The dwarf sperm whale feeds on much larger prey, including the giant squid, the colossal squid, octopuses and some fish. It may also take in other prey accidentally when feeding. Dwarf sperm whales hunt their prey using echolocation.