If you still remember your childhood stories where animals could sing or talk, here is another one of nature’s mystery: singing fish. A certain species of fish from the Pacific sings at night. Scientists from the US have discovered the secret of this species, a hormone implemented into the body of the fish. This hormone is called Melatonin.
Many seamen wondered what is this mysterious hum they have heard for years when at sea. Researchers managed to offer an answer to that question. The hum is the song of a male plainfish midshipman fish which sings to attract the female when breeding season starts.
This species can grow up to 38 centimeters long. Its color is olive-brown. The name comes from the bioluminescent organs that can be seen on the underside, and remembered scientists about the buttons from a midshipman’s uniform.
Scientists brought this species of fish down to their labs in order to analyze them and to reveal nature’s mystery. The study conducted by Professor Andrew Bass unveiled how this species of fish hummed when kept in the dark, having a constant rhythm. When the tank of water with midshipman fish was brought into the light, they stopped singing. Bass came up with an idea: he proposed to his colleagues to feed the fish with a hormone called melatonin. Later, they have noticed that the fish didn’t stop humming when brought out of the dark room. They kept singing in daylight, but without keeping a rhythm.
Bass and his team came to the conclusion that the singing of the fish, which sounded more like a horn, was manipulated by the presence melatonin in their bodies. In this way, they managed to solve nature’s mystery. This hormone works for them as an internal clock operated by light. This points out to an even bigger discovery. The human body also contains melatonin, but for us, it controls sleeping and waking cycles. For the fish, it acts exactly the opposite. The hormone represents the start button for nocturnal singing.
Another scientist that took part in the research, Dr. Ni Feng of Yale University, argues that melatonin is helpful for falling asleep faster and it also ameliorates jet lag. For the fish, it works as an alarm clock, energizing their hum.
This wooing song they use has a major role in their social interactions. The singing performance is scheduled for the time when females are more receptive. The hum starts when the fish know the predators can not hear them.
Researchers’ basic idea expressed after this study is that melatonin indicates that the brain’s circuits evolved from aquatic species up to our primate ancestors. What do you think about this outstanding discovery?
Image source: wikipedia