Ocean animals for kids: 23 sea animals to research

The ocean covers 71% of Earth and holds most of its living space, and the animals in it range from jellyfish with no brain to the blue whale, the largest animal that has ever lived. Whales, dolphins, sea otters and walruses are mammals that breathe air and must surface to do it; sea turtles are reptiles that come ashore only to lay eggs; penguins are birds that fly underwater; and sharks, seahorses and manta rays are fish. Many make huge journeys — humpback whales swim up to 8,000 kilometres each way between feeding and breeding waters, and leatherback turtles cross entire oceans. Echolocation lets dolphins and orcas find prey in dark water, and narwhals and belugas spend the winter under Arctic pack ice. Overfishing, warming seas and plastic threaten many of these species: more than a third of sharks and rays are threatened with extinction, and the vaquita porpoise is down to around ten animals.