The fish that is the ‘noisiest’ ever found by scientists – 02/28/2024 – Science

A tiny, transparent fish makes a sound as loud as a jackhammer. This is what scientists in Berlin, Germany, discovered.

They began investigating after hearing mysterious noises coming from the fish tanks in their laboratory.

They discovered that fish of the species Danionella cerebrum produce a powerful drumming in an organ called the swim bladder.

In the waters close to the fish, the sounds reach 140 decibels, which is as loud as a gunshot.

Researchers say they believe the 12-millimetre-long species is the loudest fish of its size ever found.

They suggest that “drumming” may be a form of social communication.

In most kingdoms of nature, the larger the animal, the louder the noise it makes.

Underwater it’s a different story — this tiny species is now one of the loudest ever discovered.

Scientists know that other creatures, such as snapping shrimp or pistol shrimp, can produce quite loud sounds while hunting other species, reaching up to approximately 200 decibels.

The fishes Danionella cerebrum They are valued by science because their transparency means you can see your brain in action — and this allows researchers to study your behavior up close.

But while working with these fish in their laboratory in Germany, scientists noticed something strange.

“People walked past the fish tanks and could hear these sounds, and they wondered where they were coming from,” says lead author Verity Cook, who is a PhD student at Charité University in Berlin.

“And it turned out (the sounds) were coming from the fish themselves. It’s extraordinary, because they’re so tiny and so noisy.”

With the aid of an array of microphones and video cameras, the research team was soon able to figure out how loud the sound was.

“At a distance of one body length, about 140 decibels is the amplitude of the sound, that’s how loud we believe the sound is perceived by other fish,” she tells BBC News.

“Sound attenuates with distance, so at one meter away the amplitude is about 108 decibels.”

This is still roughly equivalent to the noise made by an excavator.

Much of this sound is reflected back into the water, so when someone stands next to fish tanks they hear these pulses as a continuous hum.

Although other fish, such as Porichthys Notatus and the Pogonias chromisare noisier, they are all much larger than representatives of the species Danionella cerebrum.

“In terms of communication signals, I haven’t been able to find another animal this size that makes such loud sounds,” adds Cook.

The researchers argue that the percussion mechanism used by fish is a very sophisticated instrument.

All bony fish have a swim bladder, an organ filled with gases that helps them stay underwater.

Many species use their muscles to “drum” this organ and produce sounds, but Danionella cerebrum go further.

When muscles contract, they pull on a rib, which creates tension in a piece of cartilage inside the muscle.

When the cartilage is released, it hits the swim bladder.

Only the males of the species make this sound — and they only do it when they are in company. Some are taller than others.

“We know that when you suddenly have eight males together in a large tank, three of them will dominate the sound production, and the rest will be quiet. So we think there is some kind of hierarchy,” explains Cook.

Researchers say they believe the fact that they evolved in murky waters in Myanmar played a role in developing this ability to generate a loud noise to help them communicate.

“Evolution has created many interesting ways to solve many interesting problems,” says Cook.

“And we shouldn’t assume we know how things work, just because of how things work in other species.”

The study was published in the scientific journal PNAS (Proceedings of the National Academy of Sciences).