The toothed whales-the odontocetes-generally feed on fishes and squid. Bigg’s (transient) killer whales are the only species of cetacean that consume other marine mammals. Toothed whales typically capture their prey individually. Odontocete teeth are typically conical, and all teeth are the same size and shape. This is known as homodent dentition. The sharp teeth are used for grasping their prey, rather than chewing. Some odontocetes can have over 200 teeth, whereas some have no exposed teeth. Beaked whales catch and swallow their prey by sucking them into their mouths using muscular throat grooves.
Baleen whales-the mysticetes- are the largest of the marine mammals, but feed on some of the world’s smallest organisims. Instead of teeth, these animals have multiple rows of keratinous plates known as baleen. These plates function like a sieve to trap zooplankton and other small, schooling fish. In order to feed this way, baleen whales must strain large amounts of water, and their large mouths, pleated throats, enormous bodies support this unique feeding strategy.