One of the smallest fish in the world, just 12 millimeters long, manages to produce sounds of over 140 decibels (comparable to those of a plane taking off) thanks to an ad hoc apparatus that it uses to communicate with its peers in shallow waters and troubled areas of Myanmar.
This is indicated by the study published in the journal of the American Academy of Sciences (Pnas) by the Einstein Center for Neurosciences of the Charité University Hospital in Berlin, in collaboration with the Senckenberg Research Institute in Dresden.
"Fish are generally considered rather silent members of the animal kingdom, however - observes ichthyologist Ralf Britz, of the Senckenberg Research Institute - there are some species that can be surprisingly noisy."
On this list, the small translucent fish Danionella cerebrum stands out: the size of a fingernail, "it can produce sounds of over 140 decibels at a distance of 10-12 millimeters, something comparable to the noise that a human can perceive 100 meters away from a plane taking off", adds the expert.
To understand the secret of such power, researchers studied the fish with a mix of techniques ranging from high-speed video to microcomputed tomography to genetic analysis.
The results showed that the male Danionella cerebrum is equipped with an apparatus for generating sounds that is unique in its kind: it is made up of a cartilage that vibrates like a drum, a specialized rib and a muscle resistant to fatigue.
“This apparatus causes the cartilage to beat with a force of more than 2,000 g against the swim bladder to produce a rapid, strong beat.
These beats are sequenced to produce calls with unilateral or bilaterally alternating muscle contractions,” explains Britz.
This acoustic signaling system would have been developed by males, always in strong competition with each other, to be able to communicate despite the turbidity of the water.
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