🐟

Tuna is a rare warm-blooded fish

Do you know why fish feel cold to the touch? Because they are cold-blooded—their temperature is the same as the water temperature. In icy water, fish are cold, in warm water, fish are warm. But there is one surprising exception: tuna!

Tuna is one of the few warm-blooded fish in the world. Its body is heated by its muscles and can be 10-15 degrees warmer than the water. If the ocean is 5 degrees, the tuna inside is 20! It's like you would feel comfortable in a T-shirt in the snow.

Why does it do this? To be fast! Warm muscles work much harder. Tuna can accelerate to 75 kilometers per hour - faster than a car in the city. And it can swim for thousands of kilometers without stopping. One tagged tuna crossed the Atlantic Ocean three times - more than a person can do in a year by plane!

Interesting fact: a tuna can't stop. If it stops swimming, it will suffocate. Because water flows through its gills only when it moves. So a tuna swims its entire life — even when it sleeps. It is born and swims until it dies.

The tuna's heart beats very fast—up to 100 times per minute. It lives like a marathon runner, always on the move.

The largest tuna caught weighed 680 kilograms — as much as 10 people. The smallest one weighed only 50 grams, like a chocolate bar.

The next time you hear the word "tuna," remember: it's not just a fish, but a warm, swift torpedo that never sleeps.