This is a short video of a fisherman tossing a small tuna he caught to a school of giant trevally (sometimes called giant piranhas despite the face they're unrelated besides both being fish -- they're not even in the same order of scientific classification). A veritable feeding frenzy ensues. Not for long though, they devour the whole thing in like thirty seconds. For reference, I could not have eaten that fish so quickly, although one time I did eat two McDonald's Filet-O-Fishes in under a minute because my dad bet me a McFlurry I couldn't do it. Obviously, my mom was out of town on business that weekend. Same goes for the weekend my dad let me jump off the roof with a trash bag parachute. At least the girl I liked at school signed all my casts.
Keep going for the video.
Thanks to HV, who agrees this is exactly why you never bring a tuna to a trevally school on show-and-tell day.