So evidently, about 3% of the fish species out there have mating calls. I don’t mean dolphins or whales, I mean fish, and I don’t mean pheromones released in the water, I mean actual sound.

Fish Sounds - Ocean Life - New York Times

The above article has a video interview and some audio clips; this is some really alien, bizarre stuff. They grind their own bones against each other, fart bubbles, and some even have structures akin to vocal cords.