How one of the world's tiniest fish sounds as loud as a gunshot

The Danionella cerebrum—one of the world's tiniest fish at just 1/2 inch in length—can make a sound as loud as a gunshot close up, or a jet engine at 100 feet away. Researchers from the University of Lincoln in the UK used high-speed video and a 3D X-Ray imaging technique to find out how the fish can be so damn loud.

"We found that it possesses a unique sound production apparatus – involving a drumming cartilage, specialized rib, and fatigue-resistant muscle – which allows the fish to accelerate the drumming cartilage at extreme forces and generate rapid, loud pulses," they write in their scientific paper.

From The Guardian:

To produce sound, a rib that lies next to the swim bladder is moved by a special muscle into a piece of cartilage. When the rib is released it hits the swim bladder and makes the drumming sound. The rib is much harder in males, which explains why females do not produce sounds.

The scientists have not established why the fish make such loud sounds but suggested it could help navigate murky waters or be an aggressive tactic used by males to warn off competition.