Hormone that lulls people to sleep signals underwater fish flirting
Margaret Marchaterre/Cornell University
For widemouthed, musical midshipman fish, melatonin is not a sleep hormone — it’s a serenade starter.
In breeding season, male plainfin midshipman fish (Porichthys notatus) spend their nights singing — if that’s the word for hours of sustained foghorn hums. Males dig trysting nests under rocks along much of North America’s Pacific coast, then await females drawn in by the crooning.
New lab tests show that melatonin, familiar to humans as a possible sleep aid, is a serenade “go” signal, says behavioral neurobiologist Ni Feng of Yale University.
From fish to folks, nighttime release of melatonin helps coordinate bodily timekeeping and orchestrate after-dark biology. The fish courtship chorus, however, is the first example of the hormone prompting a launch into song, according to Andrew Bass of Cornell University. And what remarkable vocalizing it is.