🌊 Ocean animals

The ocean covers most of our planet. Near the top it is bright and warm enough for tiny floating plants, which feed tiny animals, which feed bigger ones, all the way up to the biggest animal that has ever lived. Deeper down it is dark and cold. Some ocean animals breathe water through gills, and some, like whales, come up to breathe air.

The biggest and the smallest here: the blue whale and the clownfish

🧒 our measuring child, 4 ft1.2 m🐋 Blue whale, 110 ft33.5 m long🐠 Clownfish, 3.5 in9 cm long🔍 Pip the pangolin zoomed in 100 times on the clownfish

⚖️ Compare them

31 animals here

Record holders here

Fastest: the sailfish, 68 mph109 km/h1
Heaviest: the blue whale, 165 tons150 tonnes2
Lives longest: the American lobster, 100 years100 years3

Ocean animals for kids, A to Z

🦞 American lobster: A sea animal with two very different claws and a hard shell.
🐟 Atlantic bluefin tuna: A huge, speedy fish that crosses the whole Atlantic Ocean.
🐋 Beluga whale: The white whale nicknamed the canary of the sea for its chirps.
🦀 Blue crab: A crab with paddle-shaped back legs that make it a great swimmer.
🐋 Blue whale: The biggest animal that has ever lived, bigger than any dinosaur.
🐬 Bottlenose dolphin: Each dolphin has its own whistle that works like a name.
🦭 California sea lion: It barks loudly and can walk on land using its big front flippers.
🐠 Clownfish: A small fish that lives safe inside the stinging tentacles of an anemone.
🐧 Emperor penguin: The biggest penguin, and the dad keeps the egg warm on his feet.
🐟 Giant manta ray: The biggest ray, gliding through the sea on wide, wing-like fins.
🐙 Giant Pacific octopus: The biggest octopus: soft, clever, and able to change color in a blink.
🦈 Great white shark: The biggest fish that hunts, with rows of spare teeth waiting.
🐢 Green sea turtle: It grazes on seagrass underwater, like a cow in a meadow.
🦭 Harbor seal: A seal whose whiskers can feel where a fish has just swum.
🐋 Humpback whale: Male humpbacks sing long songs that other whales learn and copy.
🐢 Leatherback sea turtle: The only sea turtle without a hard shell, and it eats jellyfish.
🐟 Lined seahorse: The dad seahorse carries the eggs in a pouch on his belly.
🐢 Loggerhead sea turtle: Named for its big head and jaws that crunch crab and clam shells.
🪼 Moon jellyfish: A jellyfish with no brain, no heart and no bones at all.
🐋 Narwhal: A narwhal's long twisty tusk is really a tooth, not a horn.
🐡 Ocean sunfish: The heaviest bony fish looks like a swimming head and eats jellyfish.
🐳 Orca: Orcas live in close families that are often led by a grandmother.
🐻‍❄️ Polar bear: The biggest bear, at home on the frozen Arctic sea ice.
🐟 Sailfish: A speedy fish with a tall back sail and a long, pointed bill.
🐊 Saltwater crocodile: The biggest reptile alive, at home in rivers and even the sea.
🦦 Sea otter: Sea otters hold hands while they sleep so they don't drift apart.
🐟 Sockeye salmon: A fish that swims home to the very river where it hatched.
🐋 Sperm whale: The biggest toothed whale, and one of the deepest divers of all.
🦭 Walrus: A walrus uses its tusks like ice picks to climb onto the ice.
🐋 West Indian manatee: A gentle plant-eater of warm water, and a cousin of the elephant.
🦈 Whale shark: The biggest fish alive is a gentle shark that eats tiny food.

NOAA National Ocean Service, Ocean Facts feed ('What is the fastest fish in the ocean?'), checked 30 October 2026.
NOAA Fisheries, checked 30 October 2026.
NOAA Fisheries, checked 30 October 2026.