The record breaker is a bump-head sunfish (Mola alexandrini). Taller than it is long, with a truncated back fin and mushroom-colored skin, the fish weighed in at just more than three tons (2,744 kilograms). This beats out the previous bony fish record holder, another bump-head sunfish caught off the coast of Japan in 1996 that tipped the scales at more than 2.5 tons (2,300 kilograms). (Cartilaginous fish such as whale sharks can grow even bigger than bony fish.)
Their food of choice is jellyfish!
Hard to believe they get that big on jellies. I suppose the explosion in jelly pops helps. Loggerhead turtles are jelly eaters. too.