Blue whales—the largest animals on Earth—live in the sea and can grow up to 100 feet.
The Arctic Ocean is the smallest and shallowest of the world’s oceans.
The Great Barrier Reef is so large it can be seen from space.
Octopuses have three hearts, and two of them stop beating when they swim.
Sea otters hold hands while they sleep to avoid drifting apart.
Some jellyfish are technically “immortal” and can revert back to an earlier life stage.