In the Gulf of Mexico, a fish called the "corvina" draws attention to itself for being more horny than a frat boy at his first keger. During mating season, they assemble in a huge mass for fornication. It's a fish orgy, to call a spade a spade.
It's not that unusual for animals to get it on in groups, but the corvinas manage to have sex while also emitting an insanely loud noise. According to the Guardian, it sounds like a machine gun going off.