A little quiz with a lot of sea in it.
Meet the animals doing their own thing underwater.
Ten questions, with the answers explained. Try them in your head, then open each answer when you're ready.
Play this quiz →QUESTION 1 / 10
Which of these animals is a mammal?
- Shark
- Dolphin
- Octopus
- Tuna
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Dolphin
Dolphins breathe air, give birth to live young, and feed their young milk.
QUESTION 2 / 10
What do most fish use to extract oxygen from water?
- Feathers
- Gills
- Lungs
- A blowhole
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Gills
Gills allow most fish to take dissolved oxygen from water.
QUESTION 3 / 10
Which animal has eight arms?
- Squid
- Lobster
- Octopus
- Sea horse
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Octopus
An octopus has eight arms. A typical squid has eight arms plus two longer tentacles.
QUESTION 4 / 10
What is a baby sea turtle called?
- A joey
- A foal
- A calf
- A hatchling
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A hatchling
A newly hatched turtle is a hatchling. It faces a risky journey from nest to sea.
QUESTION 5 / 10
What creates a pearl inside an oyster?
- A fish egg
- Sand turning to glass
- Layers of nacre
- Frozen seawater
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Layers of nacre
The oyster deposits layers of nacre around an irritant or implanted nucleus.
QUESTION 6 / 10
Which of these is a crustacean?
- Jellyfish
- Sea anemone
- Lobster
- Dolphin
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Lobster
Lobsters are crustaceans, a group that also includes crabs and shrimp.
QUESTION 7 / 10
Which marine mammal has long tusks?
- Seal
- Walrus
- Manatee
- Otter
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Walrus
A walrus's tusks are elongated canine teeth used for display and other tasks.
QUESTION 8 / 10
What is coral built by?
- Crystallized salt
- Underwater tree roots
- Tiny animals called polyps
- Fish scales
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Tiny animals called polyps
Coral polyps are animals. Many reef-building species make calcium carbonate skeletons.
QUESTION 9 / 10
Which of these animals is a fish?
- Sea cucumber
- Sea lion
- Sea anemone
- Sea horse
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Sea horse
Despite its unusual shape, a sea horse is a fish with gills and fins.
QUESTION 10 / 10
What is the largest living animal?
- Whale shark
- Blue whale
- Giant squid
- African elephant
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Blue whale
The blue whale is the largest living animal. It feeds mostly on tiny krill.