Scientists Find 12-mm-long Fish Produces Sound As Loud As A Gunshot

In a recent discovery, scientists found that one of the world’s smallest fish, the male Danionella Cerebrum, measuring the width of an adult human fingernail emits a sound as loud as a gunshot. Found in the streams of Myanmar, the fish measures about 12 mm.

Researchers have discovered that the fish produces clicks reaching 140 decibels, similar to the intensity of an ambulance siren or gunshot, as reported in the PNAS journal.

According to the paper, fish usually make sounds by vibrating their swim bladder. This organ, filled with gas, helps them stay afloat. They do this using special muscles that contract rhythmically, like drumming. The sound pulses produced by the Danionella cerebrum, known for having the smallest brain among vertebrates, have baffled scientists. Swim bladder-related muscle mechanisms failed to explain where the sound came from convincingly.

Researchers at Charité University in Berlin have discovered that the fish has a distinctive system for producing sounds. This system involves drumming cartilage, ribs and muscles resistant to fatigue. These features help them to accelerate the drumming cartilage with tremendous force, resulting in rapid and loud pulses of sound.

The researchers stated that understanding this adaptation helps them learn more about how animals move. It also shows the amazing variety of ways different species move. “This adds to our knowledge of how living things have changed over time and how their bodies work,” the paper mentions.

The team of scientists used high-speed video recordings to study how the sound was made. During the sound production process, a specific muscle displaces a rib located near the swim bladder onto a piece of cartilage. Upon release, this rib hits the swim bladder, producing the drumming sound. Males have a much harder rib, which is why females don’t make sounds.

The scientists haven’t figured out why Danionella Cerebrum make such loud sounds. They think it might help them move around in water that’s not clear or be a way for males to warn other males to stay away. Danionella Cerebrum is a cyprinid fish species found in turbid low-altitude streams along the southern and eastern slopes of the Bago Yoma mountain range in Myanmar.