Mystery solved: Melatonin makes these fish sing at night
Mystery solved: Melatonin makes these fish sing at night
By Rachel Feltman
September 23 at 2:27 PM
There are fish that sing. Or drone like a bunch of loud kazoos, anyway. People living in houseboats in the San Francisco Bay have grown used to a low, strange hum that begins suddenly in the dark of the night and stops just as abruptly in the early morning.
The noise comes from male suitors of the species Porichthys notatus, commonly called the plainfin midshipman fish. While female midshipman only grunt when showing aggression, the males trying to mate with them use their swim bladders to create noises that have been likened to a chorus of kazoos, a formation of flying jets or a swarm of droning bees.
"They sound like an orchestra full of mournful, rasping oboes," SFGate reported in 2004.
Researchers now believe they've figured out how the midshipman keeps his crooning so punctual: melatonin. Melatonin is a hormone produced by many plants and animals, its release triggered by darkness. In animals that sleep at night as humans do melatonin is thought to help regulate the internal "clocks" that tell our bodies it's time for some shut-eye. Some humans even find respite from insomnia by taking melatonin supplements at bedtime.
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More:
https://www.washingtonpost.com/news/speaking-of-science/wp/2016/09/23/mystery-solved-melatonin-makes-these-fish-sing-at-night/