Tiny fish stuns researchers by generating sound as loud as a gunshot

New Delhi, India

Researchers have revealed that the male Danionella cerebrum, a tiny fish measuring approximately the width of an adult human fingernail and found in the streams of Myanmar, possesses the capability to produce sounds as loud as a gunshot.

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According to a study published in the PNAS journal, these aquatic creatures, with a length of about 12mm, emit sounds exceeding 140 decibels, equivalent to the volume of an ambulance siren or jackhammer.

Traditionally, fish generate sounds through the vibrations of their swim bladder, a gas-filled organ responsible for buoyancy control, driven by rhythmic contractions of specialised "drumming" muscles, as noted in the paper.

However, the sound production mechanism of the pulses produced by the Danionella cerebrum, which boasts the smallest known brain among vertebrates, remained elusive, as the swim bladder-related muscle mechanisms did not offer a plausible explanation for the origin of the sound.

Researchers from Charité University in Berlin unraveled the mystery, discovering that the fish employs a unique sound production system featuring a drumming cartilage, specialised rib, and fatigue-resistant muscle.

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This allows the fish to accelerate the drumming cartilage at extreme forces, generating rapid and loud pulses.

The study highlighted, "Understanding this extraordinary adaptation expands our knowledge of animal motion and highlights the remarkable diversity of propulsion mechanisms across species, contributing to our broader understanding of evolutionary biology and biomechanics."

High-speed video recordings were instrumental in investigating the mechanism of sound production. To produce sound, a rib situated next to the swim bladder is moved by a specific muscle into a piece of cartilage.

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Upon release, the rib strikes the swim bladder, creating the distinctive drumming sound. Notably, the rib is considerably harder in males, explaining why females do not produce sounds.

While the scientists have not determined the exact purpose of the fish's loud sounds, they suggest potential roles such as aiding navigation in murky waters or serving as an aggressive tactic employed by males to ward off competition.

(With inputs from agencies)