Deep-water fish called opah appear to be the first fully warm-blooded fish species ever discovered, according to a new paper published in Science. Researchers say the unique biology behind opah, also known as moonfish, allow the species to operate at peak performance even within frigid ocean depths.
Opah is the first fish that can circulate warm blood throughout the entire body, and that gives it some advantages over tuna and shark species,” Wegner says. “Since they can keep their entire bodies warm, they can stay down deep, continuously close to their forage base.”
