Fun facts about tuna: Uncanned and wild

This is how most people know tuna:

We put it on sandwiches and salads. But do you ever think of tuna as a fantastic animal, speeding wildly through the ocean?

Let’s get to know the real tuna.

1. How did tuna end up in cans to begin with?

In 1903, a California seafood canner named Albert Halfhil had a bunch of empty sardine cans lying around. The 1903 sardine catch was lousy, so he had the idea to put albacore tuna in the cans instead. It took a while, but soon people started liking canned tuna. Now, this is how most people around the world experience tuna.

In 2024, the amount of tuna caught, canned, and sold worldwide was worth about $44 billion. The tuna industry provides humans with millions of jobs catching, canning, and selling tuna.

2. Before the fishhooks, nets, and cans, there is tuna, the wild animal

Tuna are sleek wild fish. The largest tuna species, the Atlantic bluefin tuna, can grow as big as a polar bear.

Tuna swim in all oceans, especially in tropical and temperate waters.

Tuna live in schools. No, not elementary or middle schools. They live in groups called schools. Some tuna schools can have thousands of individuals, depending on the species.

3. There are 15 species of tuna

Skipjack, albacore, and yellowfin tuna are the species we most often buy in cans.

You can find guides on how to eat tuna sustainably, such as this one from Monterey Bay Aquarium’s Seafood Watch.

4. Tuna are built for speed

Tuna are fusiform, meaning shaped like a football, with a thick middle and a narrow head and tail. This shape helps them shoot through the water without much resistance, the way a football cuts through air.

Some tuna species can swim up to 45 miles per hour! They accomplish this feat in part by warming up their muscles with the heat generated from their constant motion. This heat is circulated through their bodies with a special system of blood vessels that insulates them from losing heat to the ocean. 

Tuna are partially warm-blooded, unlike most fish. This allows them to zoom through cold waters.

5. Tuna are active hunters … and actively hunted 

Schools of tuna zoom through the ocean hunting down schools of smaller fish, like herring and anchovies. Tuna speed, facilitated by their sleek bodies and warmed muscles, makes them active and effective predators.

Tuna have to watch out, though. They are not just predators, but prey. 

Sharks, dolphins, and marlins like to eat tuna, like humans, and actively hunt them down.

Nobody has discovered yet what toppings sharks put on their tuna sandwiches.

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