According to Wikipedia:
Opah (also known colloquially as moonfish, sunfish, kingfish, redfin ocean pan, and Jerusalem haddock) are large, colorful, deep-bodied pelagic Lampriform fish comprising the small family Lampridae (also spelled Lamprididae). There are only two living species in a single genus: Lampris (from the Greek lamprid-, “brilliant” or “clear”). One species is found in tropical to temperate waters of most oceans, while the other is limited to a circumglobal distribution in the Southern Ocean, with the 34th parallel as its northern limit.

Opah are rarely caught by recreational anglers. They are prized trophies for deep-water anglers as their large size and attractive form lend themselves well to taxidermy. Opah are frequently caught as bycatch in many longline tuna fisheries. Opah is becoming increasingly popular in seafood markets. It first became popular as a sushi and sashimi in the late 1980s and early 1990s. The meat is lightly flavored and lends itself well to a variety of preparations. Opah flesh has a light pink to orange color. It is popular in Hawaii, especially in restaurants. An average of 35 percent of an opah’s weight is consumable, with the remaining 65% being bone and thick skin.