Time for 10 Ocean Trivia Questions

Test your ocean knowledge with ocean trivia

How much do you really know about the ocean? Here is your chance to test your knowledge with our ocean trivia quiz. Each question is followed by a photo and then the corresponding answer before moving onto the next question. Will you score a perfect 10/10? There is only one way to find out. Let’s get started…

   1. True or false: Octopuses have tentacles.

    • True

    • False

A large red octopus swims along the ocean floor

Answer: False—They actually have arms, not tentacles. While animals like squid and cuttlefish have arms and tentacles, octopuses are more simple: they have 8 arms with trademark suckers. You can see tentacles on other cephalopods—they have suckers only by the end.

2. How many hearts do octopuses have?

    • 1 heart

    • 8 hearts

    • 2 hearts

    • 3 hearts

An octopus swims near the sea shore

Answer: They have 3 hearts! While one keeps blood supply flowing to various organs, there are 2 more that are responsible for pumping blood by the gills so they can pick up oxygen.


3. What is the largest sea turtle in the world?

    • Loggerhead

    • Kemps ridley

    • Leatherback

    • Hawksbill

Beautiful Topsail Beach Sunrise.

Answer: The leatherback—they can weigh up to 2,000 pounds!

4. Kelp has roots.

    • True

    • False

A kelp forest in the ocean

Answer: FalseKelp does not have roots. Instead, it is secured by holdfasts that lock onto substrates made of rock, or cobble.

5. What is the fastest fish in the ocean?

    • Bonita

    • Wahoo

    • Sailfish

    • Swordfish

oceanscape with a beautiful setting sun

Answer: Sailfish—they have been clocked at speeds over 68 mph.

6. Which U.S. state has the greatest amount of oceanic coastline, with more miles of coastline than all the rest of the United States combined?

    • California

    • Alaska

    • Florida

    • Hawaii

Aerial video oregon coastline

Answer: Alaska—The Alaskan coastline extends for 6,640 miles, a distance greater than that of all the other states’ coastlines combined. Including islands, Alaska has 33,904 miles of shoreline.

7. What is the biggest animal on Earth?

    • African elephant

    • Blue whale

    • Whale Shark

    • Elephant seal

the sun shines over an ocean shore

Answer: Blue whale—Blue whales are massive. An adult female can grow to 100 feet long—about the length of a Boeing 737. Blue whales can weigh up to 200 tons (400,000 pounds)! That’s 30 times heavier than an African elephant. In fact, just their tongue can weigh as much as an elephant. Blue whales aren’t just the biggest animals alive in the ocean. They’re not just the biggest animals alive in the world. They are the biggest animals that have ever lived (that we know of, at least). Even the largest dinosaur can’t compare—the Argentinosaurus clocked in at about 220,000 pounds.

8. How many brains does an octopus have?

    • 9

    • 2

    • 1

    • 16

Octopus dance by Morten Brekkevold

Answer: 9—Octopuses have 9 brains because, in addition to the central brain, each of 8 arms has a mini-brain that allows it to act independently while staying in communication with the central brain.

9. This animal is the longest-living vertebrate on Earth.

    • Loggerhead sea turtle

    • Bowhead whale

    • Greenland shark

    • Blue whale

An ocean wave breaks


Answer: Greenland sharks—Scientists recently discovered a 400-year-old female Greenland shark, who set a new record for the oldest living vertebrate! The oldest living human only lived to 122.

10. What is the largest fish in the sea?

    • Whale shark

    • Mola mola

    • Giant manta ray

    • Basking shark

A school of Sardine fish in the ocean

Answer: Whale shark—they can grow up to 40 feet long and weigh up to 20,000 pounds. That is as tall as two giraffes stacked on top of each other and the weight of two elephants combined!

How many did you get correct? Were you top of the class or do you need to brush up on your ocean knowledge a little more?

Challenge your friends! Share the ocean trivia with your friends and see how they compare.

Keep learning with Ocean Conservancy’s Wildlife Library—you are sure to discover something new about the ocean.

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