First ever fish found to have a warm heart and maintain a high body temperature has been hiding in plain sight for years on our dinner plates.

But new research is turning this well-known knowledge on its head with the discovery of the world’s first warm-blooded fish — the opah.

This fish, the southern opah, lives in colder waters than the northern opah, so it would be harder to keep warm, Wegner said -- but even more beneficial. Were dinosaurs warm- or cold- blooded?

That makes the opah (Lampris guttatus) the first warm-blooded fish every discovered. Most fish are exotherms, meaning they require heat from the environment to stay toasty.

But as new research reveals, the deepwater opah has the unprecedented ability to circulate heated blood throughout its entire body, making it the only known fully warm-blooded fish.

As it turns out, it’s the only “truly warm-blooded fish,” according to National Geographic — and it’s pretty fast, to boot. Usually, a fish's overall temperature matches the water it's in ...

There’s nothing about the opah that says “fast-moving predator”. Tuna, sharks, and swordfish are fast-moving predators and accordingly, their bodies look like streamlined torpedoes. By ...

Warm-blooded fish is an agile predator. An opah captured during longline surveys by the Southwest Fisheries Science Center. NOAA Fisheries West Coast — -- With its tire-sized frame and ...

Move over, mammals and birds, and make room for a fish called the opah in the warm-blooded club. Researchers said in the journal Science on Thursday that this deepwater denizen is the first fish ...

Tuna, opah, and billfishes such as marlins and swordfish are among the 0.1% of fish species that are warm-blooded. Evidence ...

Most fish are cold-blooded, which means that they rely on the temperature outside of their body to regulate their internal temperatures However, some sharks are surprisingly warm-blooded, storing ...