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Fun Facts About Atlantic Tunas

November 14, 2023

How much do you know about Atlantic tunas? Some of these facts might be surprising!

Bluefin tuna swimming in water.

In celebration of our Atlantic Tunas Art Contest, we wanted to share some interesting facts and hopefully inspire this year’s young artists!

1. Tunas come in many sizes. 

Western Atlantic bluefin tuna are the largest of the Atlantic tuna species. They can grow up to 13 feet long and weigh up to 2,000 pounds! They have a long lifespan, living 20 years or more, and generally don’t spawn until they are 8 years old. 

Atlantic skipjack tuna are among the smallest, weighing in at 40 pounds and measuring around 3 feet long. They grow up fast, spawn when they are 1 year old, and have a relatively short lifespan of 7 years.

2. Tunas are very fast swimmers.

Thanks to their unique torpedo-shaped bodies, smooth skin, and streamlined fins, tunas are fast swimmers. Albacore tuna can swim faster than 50 miles per hour. This helps them catch prey, avoid predators, and cover a lot of ground quickly during annual migrations.

3. Bluefin tunas are warm blooded.

Some tunas—like bluefin tunas—are warm-blooded, like mammals. They are able to keep their body temperature warmer than the water around them thanks to a specialized blood vessel structure, called a countercurrent exchanger. This gives them several advantages over cold-blooded fish. 

Regulating their own temperature means tuna can live in a wide range of conditions, and can be found in arctic and tropical waters. The extra heat in their muscles gives them a boost in power and speed. It also helps them dive deep, reaching depths of 500 to 1,000 meters to search for food and to avoid predators.

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bluefin tuna
Bluefin tuna. Credit: iStock

4. Albacore tunas, like all tunas, never stop swimming.

If you could follow an albacore tuna around the ocean, you would notice something strange: it never stops moving. Like all fish, they need oxygen to fuel their bodies, pulling it from the water through special organs called gills. Unlike other fish, they lack the structures needed to pump water over their gills. 

Instead, albacore tuna swim with their mouths open, allowing water to flow in and wash over their gills. They have adapted to life on the go, with their very long pectoral fins allowing them to save energy by “gliding” through the water.

5. Tunas travel the oceans in schools that can number in the thousands.

Tunas travel together in groups called schools. They migrate great distances between hunting grounds and spawning grounds. These schools can include hundreds or thousands of fish. For example, albacore tunas travel together in schools that can be up to 19 miles wide! 

Swimming in schools gives tuna an edge over prey when hunting. Having many eyes scanning the sea also helps them spot and avoid predators. It's not unusual to see schools that include a variety of tuna species including albacore, skipjack, yellowfin, and bluefin.

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Bluefin tuna fish swimming together.
School of bluefin tuna. Credit: iStock

6. Tunas are known for being top predators—but they are also prey.

All tuna species are predators. Their torpedo-shaped bodies give them an advantage over slower, less maneuverable species and their sharp vision helps them catch prey. Tunas eat a varied diet including fish, crustaceans, and squid. The smaller skipjack tuna are opportunistic feeders, preying on a variety of fish including herrings, crustaceans, cephalopods, mollusks, and sometimes other skipjack tunas. 

Tunas are also a favorite prey species for top ocean predators. A tuna’s speed and agility comes in handy when avoiding hungry sharks, billfish, and toothed whales. Smaller tuna species (like skipjack) and juveniles also have to avoid other larger tunas looking for a meal.

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Yellowfin tuna swimming underwater away from tiger shark.
Yellowfin tuna swimming away from a shark. Credit: iStock

7. Tunas have their own day!

May 2 is World Tuna Day—named by the United Nations to highlight the global importance of sustainably managing tuna fishing stocks in the world’s oceans. This ensures they will be swimming in the world’s oceans long into the future. NOAA Fisheries, with the help of tuna fishermen, sustainably manage tuna fisheries in U.S. waters.

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School of tuna swimming underwater.
School of tuna. Credit: iStock

8. Fishing for tuna is an ancient practice.

Cave paintings found near Sicily provide the best evidence that humans have been fishing for tuna for a long time. The paintings feature bluefin tuna and date from around 9200 years BCE. Archeologists believe tuna were actively fished in the Mediterranean and have found evidence of this in Greece, Croatia, France, and Spain. 

Last updated by Office of Sustainable Fisheries on November 16, 2023