How are dolphins, whales and porpoises different from each other?
Cetaceans are divided into two groups – those with teeth and those without teeth. Toothed whales (Odontocetes [oh-don’t-oh-seat-s]) are predators that use their peg-like teeth to catch fish, squid, and marine mammals. The sharp teeth help them catch their slippery prey (the animals they hunt). Most toothed whales swallow their food whole, without chewing it first. They have one blowhole (nostril) and use echolocation to hunt. Toothed whales communicate with high-frequency sound (clicks, whistles, squeaks, squawks). Toothed whales tend to travel in highly organized groups with a social hierarchy. The Odontocetes or toothed cetaceans include all the dolphins and porpoises and beaked and sperm whales. Baleen whales (Mysticetes [miss-ta-seat-s]) are large predators that filter enormous amounts of small fish, shrimp-like creatures called krill and tiny animals called zooplankton from the water. Instead of teeth they have large, stiff bristles (baleen), which hang down from their upper jaws.
