A new study released this week has revealed that one of the world’s smallest fish can make a pretty loud sound.
Known by its scientific name, danionella cerebrum, the fish is transparent and can grow up to half an inch long; but what fascinates scientists is the fish’s lack of a skull, yet they have the smallest brain of any vertebrate animal, per Smithsonian Magazine.
What we know about danionella cerebrum
The little fish is known to be about the length a fingernail’s width, per The Guardian, and are originally from Myanmar, according to BBC.
Scientists had come across the danionella cerebrum’s noises by accident when walking by a fish tank full of them and hearing noises coming from it, according to a co-author of the study, per BBC.
According to Smithsonian Magazine, the study explained how these scientists split up the fish into small groups in separate tanks and took videos to figure out why and how the fish made the noise.
Scientists found the noise was made in the swim bladder
While taking the videos, scientists found that danionella cerebrum had “a unique sound production system, involving a drumming cartilage, specialized rib and fatigue-resistant muscle,” according to The Guardian. To create its unusual loud sound, the fish’s body would move a rib into the drumming cartilage, which then releases the rib and hits the swim bladder.
This creates the drumming-like noise scientists had heard, and according to Smithsonian Magazine, the muscle that pulls the rib back has a longer endurance rate than the rest of the muscles in the fish’s body, allowing danionella cerebrum to make percussive noises.
They also found in the study that only male danionella cerebrum can create this noise, most likely due to their rib bones being more larger and rigid according to Smithsonian Magazine. Overall, the study concluded that the sounds could exceed 140 decibels, per The Guardian.
The amount of 140 decibels is equivalent to a fireworks show, according to the National Institute on Deafness and Other Communication Disorders.
But danionella cerebrum is not the only fish capable of making such noises. According to the BBC, larger fish, such as the Plainfin Midshipman and the Black Drum, are known to scientists to make similar noises.
Scientists still aren’t exactly sure why danionella cerebrum makes these noises. According to Smithsonian Magazine, the 140 decibel range is very loud for such a small fish, with scientists explaining in the new study that it could be a communication method or a way to attract mates.