The Danionella cerebrum fish, one of the world’s smallest, can produce sounds as loud as a gunshot, reaching over 140 decibels. This fish found in Myanmar streams has a unique sound production system involving a drumming cartilage, specialised rib, and fatigue-resistant muscle, allowing it to generate rapid, loud pulses. The fish has the smallest known brain of any vertebrate. Scientists at Charité University in Berlin discovered this mechanism using high-speed video recordings. The reason for the loud sounds is still unknown, but it could be for navigation or as a competitive tactic by males. This finding contributes to our understanding of evolutionary biology and biomechanics.
https://www.theguardian.com/science/2024/feb/27/smallest-fish-sounds-loud-danionella-cerebrum