Otoliths: Fish Hearing Bones
Fish Hearing and Otoliths
Did you know fish and invertebrates that live under water make sound? Of course we've all heard of dolphin clicks, whale songs, and haunting melodies by marine mammals, but there's a much richer symphony of sound that occurs under water. Water is a perfect medium because sound waves can travel quite far in vast regions, and areas of reduced visibility. Fish can find mates, signal danger, sense vibrations, and find food/prey all by sensing sound under water.
Depending on the species, fish make a wide variety of sounds, from grunts and clicks to honks, burps, purrs, whistles, hums, groans, and growls. I had a particularly aggressive flounder that used to vibrate his 800 gallon aquarium in breeding season, and he made growling sounds (often before leaping at the naturalist). Many of the sounds that fish make are vocalizations like we make, though some are byproducts of feeding or swimming. It's thought that over 150 species of fish on the East coast vocalize. Fish that make sounds are called soniferous (sound-producing). Check out the research by Dr. Rodney Alan Roundtree and New England soniferous fish.
I know you're dying to hear some sounds, so here are a few examples, the first is the vocalization of the oyster toadfish, the next is a the croaker fish croaking, and a gronco or grunting fish from Cuba grunting like a pig.