"...
Atmospheric Administration (NOAA) determined that
unlike other fish, opah generate heat as they swim
and distribute the warmth throughout their entire
disc-shaped bodies by special blood vessels. Special
"counter-current heat exchangers" in their gills
minimize heat loss, allowing the deepwater predators
to keep their bodies several degrees above the water
temperature 250 feet down..."
http://www.usatoday.com/story/tech/2015/05/14/warm-blooded-fish-discovered/27318727/
