There are already known species of fishes which are capable of warming just some part of their body like the eye area and the brain. However, just very recently, scientists have found and was able to determine this fish that is able to warm its whole body. This fish is commonly called the moonfish but scientists called it opah.
Accordingly, Opah is a deep-sea spender as it stays and spends most of its lifetime hundreds of feet beneath the ocean surface. It is the part of the ocean where the water is such cold and a no-to-little light is able to penetrate.