Opah

This very large pelagic fish is found worldwide in tropical and temperate waters, most commonly at about 1200 feet depth, but down to 1600 feet. It is the only known full body warm blooded fish. It is often caught as by-catch in deep water Tuna fisheries, but there is currently no established market for it, so most is wasted. The U.S. National Marine Fisheries Service has issued grants to build a commercial market for this fish, as it is considered an excellent eating fish. This fish is IUCN Red Listed LC (Least Concern).   Photo by U.S. National Oceanic and Atmospheric Administration = Public Domain.

More on Varieties of Fish (very large page).

A sushi chef using Opah says, "It's like seven fish in one". The Abductor Muscle behind the head is red meat similar to that of land animals. The Top Loin is red-orange and similar to Ahi Tuna. Some have called it like a cross between Tuna and Salmon. The Belly meat is pink, fatty and particularly good for grilling or roasting. The bones make and excellent fish stock.

Buying:   Opah Top Loin and Opah Belly are available from Catalina Offshore Products - when they have it in stock. They have been granted funds by the U.S. National Marine Fisheries Service to promote this fish, but supply is still erratic (late 2018).