Chambered Nautilus

The blue whale is the largest known animal to have ever lived on Earth, even bigger than the largest dinosaurs. Despite their massive size, these gentle giants feed almost exclusively on krill—tiny shrimp-like creatures. A single adult blue whale can consume up to 4 tons of krill per day. They are baleen whales, meaning they filter ocean water through fringed plates in their mouths. Blue whales are also among the loudest animals, communicating via low-frequency groans and pulses that can travel hundreds of miles underwater.

The green sea turtle is one of the largest sea turtles and the only herbivorous species among them. They are named not for the color of their shells, but for the greenish color of their subdermal fat, which is stained by their diet of seagrasses and algae. Green sea turtles migrate incredibly long distances between feeding grounds and the nesting beaches where they were born. Their streamlined shells and paddle-like flippers make them exceptionally graceful swimmers.

The great white shark is the world's largest known predatory fish and an apex predator of the oceans. It has a powerful, torpedo-shaped body, dark gray back, and clean white underbelly, providing excellent camouflage known as countershading. Armed with up to 300 serrated, triangular teeth arranged in multiple rows, it is a formidable hunter. Great whites possess a highly developed sense of smell and special receptors called the Ampullae of Lorenzini that detect the weak electromagnetic fields generated by living creatures.