Opah

The opah is a striking deep-sea fish with a round, flattened body and vibrant colors. It roams the open ocean, far from shore, where its unusual shape helps it glide through the water. Unlike most fish, it's one of the few known to be warm-blooded, giving it an edge in chilly depths.

• Its body is nearly circular, like a dinner plate with fins.
• Sometimes called moonfish for its silvery, shimmering scales.
• Belongs to a small family of fish with only one living genus.