Small Fish Use Special Drumming Mechanism To Produce Loud Sound

A recent study reveals that one of the world's smallest fish, discovered only three years ago, employs a particular drumming mechanism to make sounds as loud as a pneumatic drill.

Powerful Pulses Of Sound

Danionella cerebrum, a tiny translucent fish that lives in shallow seas off Myanmar, can emit noises of more than 140 decibels, an international team of scientists reported.

Because of its small size, translucent body, and simplicity of study at the cellular level under a microscope, the fish is often regarded as an emerging model organism in biomedical research.

Since the species' discovery in 2021, scientists have been mystified as to how this fish, measuring less than 12mm in length - slightly longer than a fingernail - could generate sounds topping 140 decibels.

Researchers have discovered that it has a distinct sound production apparatus, which includes a specific cartilage, a distinctive rib, and fatigue-resistant muscles.

According to scientists, these characteristics enable the fish to accelerate its cartilage at high speeds and produce fast, powerful pulses of sound.

"This is comparable to the noise a human perceives of an airplane during take-off at a distance of 100 meter and quite unusual for an animal of such diminutive size," said study author Ralf Britz, an ichthyologist at the Senckenberg Natural History Museum in Dresden, Germany, in the press release.

Large animals can make louder noises than small ones. Elephants, for example, can create sounds of up to 125 decibels using their trunks.

However, some little species, such as snapping shrimp, can create extraordinarily loud noises for their size, with their claws producing cracking sounds of up to 250 decibels, according to the statement.

Some fish species produce extraordinarily loud noises, such as the male plainfin midshipman fish, which can make mating calls up to 130 dB, but Danionella cerebrum appears to be unique among fish.

Swim Bladder And Movement

The study discovered that the fish's sound output correlates with the quick compression of its swim bladder and the movement of its fifth rib.

Researchers also discovered that the D cerebrum contains specific muscles that contract to pull the fifth rib.

Scientists claim that the muscular contraction occurs at record-breaking speeds, exceeding the fastest known movement in the animal realm.

Further analysis of the mechanism revealed that the fish's fifth rib latches into a groove in a cartilage structure and creates tension by tugging on the cartilage.

The cartilage then snaps free, traveling at 2,000 times the acceleration of gravity and striking the swim bladder, resulting in a short, loud sonic pulse.

Scientists also discovered that the fish's genetic adaptations prevent exhaustion in its sonic muscles, allowing the species to emit a sustained series of sonic pulses.

"No other fish has been reported to use repeated unilateral muscle contractions for sound production," reads the study.

The findings call into question the long-held belief that the speed of skeletal movement in vertebrates is restricted by muscle activation.

This also sheds more light on the variety of adaptations for motion and sound generation found in animal species.