Tiny fish makes very big noise

LONDON, Feb 27 (BBC): A tiny, transparent fish makes a sound as loud as a jackhammer, scientists in Berlin have discovered. They were prompted to investigate after hearing mysterious clicking noises coming from the fish tanks in their lab.
They found that the fish, Danionella cerebrum, drums out a powerful rhythm on an organ called a swim bladder. In the waters close to the fish, it taps out 140 decibels, which is as loud as a gunshot.
Researchers believe the 12mm long species is the loudest fish for its size yet found. They believe the drumming may be a form of social communication.