Atlantic bluefin tuna Facts for Kids

Thunnus thynnus · THOO-nus THIN-us

A huge, speedy fish that crosses the whole Atlantic Ocean.

🏃 speed: not yet checked
⚖️ 1 tons910 kg1
📏 13 ft4 m1 long
🎂 20 years20 years1
🍽️ fish
Doing fine (Least Concern)

The bluefin tuna is a big, fast fish. Its smooth body is shaped for speed. It swims far across the ocean.

A bluefin tuna has a smooth, round body and a stiff tail that swishes quickly, so it zips through the water. Unlike most fish, it can keep its body warmer than the sea around it. It never stops swimming, because moving water over its gills is how it breathes.

Atlantic bluefin tuna are among the biggest bony fish in the sea. Their fins fold into slots on the body, so water slides over them smoothly, and warm muscles let them hunt in cold water. Tagged bluefin have swum from one side of the Atlantic to the other, hunting herring, mackerel and squid in groups called schools. People fished bluefin so heavily that their numbers fell, so countries now agree on catch limits, and the fish are slowly coming back.

How big is a Atlantic bluefin tuna?

🧒 our measuring child, 4 ft1.2 m🐟 Atlantic bluefin tuna, 13 ft4 m long

Atlantic bluefin tuna in numbers

Length	13 ft4 m1maximum
Height at the shoulder	no checked number yet
Weight	1 tons910 kg1maximum
Top speed	no checked number yet
How long it lives	20 years20 years1
What it eats	herring, mackerel, squid and other fish
Where it lives	the Atlantic Ocean, from the cold north down to the warm Mediterranean Sea
What kind	Fish
Is it in danger?	Doing fine (Least Concern)2

A number we couldn’t find on a page we trust says so, instead of guessing.

Wow!

Its fins fold into slots on its body to swim smoothly.
Tagged bluefin have swum all the way across the Atlantic Ocean.
It can keep its body warmer than the sea around it.

Compare the Atlantic bluefin tuna

Friends and neighbours

Three questions

What does the Atlantic bluefin tuna eat?

Plants and animalsFishBugs

The answer: Fish. It eats herring, mackerel, squid and other fish.

Where does the Atlantic bluefin tuna live?

FarmOceanDesert

The answer: Ocean. It lives in the Atlantic Ocean, from the cold north down to the warm Mediterranean Sea.

Which is longer, the Atlantic bluefin tuna or the cheetah?

The cheetahThey're the sameThe Atlantic bluefin tuna

The answer: The Atlantic bluefin tuna. Look at them side by side on the compare stage.

Books about the Atlantic bluefin tuna, free at the library

Ask a grown-up to tap the button: it shows where to borrow a book about the Atlantic bluefin tuna for free.

Where these numbers come from

NOAA Fisheries, checked 30 October 2026.
Wikidata, from the IUCN Red List, checked 30 October 2026.
Wikidata, Atlantic bluefin tuna (Q214415), checked 30 October 2026.