One fish, two fish, red fish, blue fish.
From there to here, from here to there,
funny things are everywhere.
So wrote Dr. Seuss in his 1960 classic.
But nowhere among the cold fish—the only kind known to Seuss, or to science—was there a warm fish.
Now researchers have discovered that the opah is in fact just that. It pumps heated blood through its body as if it were a mammal or a bird.
It’s a fish even Seuss didn’t imagine.