Why does an octopus have three hearts? What is a whale’s blowhole for? Here are 15 curious questions about the deep sea, with short and correct answers in simple words for kids aged 3 to 8. Read one a night or all at once.
Sea animals and their secrets
- Why does an octopus have three hearts? Two of them send blood to the gills, where the octopus takes in the air that is dissolved in the water. The third sends blood to the rest of the body, which gives it the energy to swim and hide.
- Who carries the seahorse’s eggs? Dad does! The male seahorse keeps the eggs in a little pouch on his belly until the babies are ready to be born.
- How does a whale breathe underwater? It does not. A whale is a mammal and breathes air, just like us, so it swims up to the surface to fill its lungs.
- What is a whale’s blowhole for? It is the whale’s nose, on top of its head. That way it can breathe without lifting its whole body out of the water.
- Does a starfish have a brain? Not a central brain like ours. It has nerves spread through its body and arms that help it feel what is around it.
- Why does a jellyfish have no brain? Its body is very simple, and a net of nerves is enough to sense the water and react. It does just fine, floating through the sea.
- How does a dolphin sleep without drowning? It sleeps with half of its brain at a time. The other half stays awake so the dolphin can swim up and breathe when it needs to.
- What is octopus ink for? When it is in danger, the octopus squirts a dark cloud into the water. It makes it hard to see, and the octopus escapes.
The deep blue and the life in it
- Where does a sea turtle go to lay her eggs? Many female sea turtles return to the beach where they were born. They swim a very long way across the ocean to get there.
- How does the lanternfish make light in the dark? It has tiny spots on its body that make their own light. This is called bioluminescence, and it helps these fish live where the sun never reaches.
- Why is the deep sea dark? Sunlight fades as the water gets deeper. Far down below, no light reaches at all.
- Why is seawater salty? It holds dissolved salts that came from rocks and land and were carried to the sea by rivers. That is why we cannot drink it.
- Is coral a rock? No! Corals are tiny animals that live together and build reefs. Those reefs become homes and hiding places for lots of fish.
- How do fish breathe? With gills. Gills take in the air mixed into the water, so a fish does not need to come up to breathe.
- Is a sea urchin an animal or a plant? It is an animal, a cousin of the starfish. Its spikes protect it from anyone who wants a snack.
