Moonlight Sonata, a fish species which holds a singing mystery from many decades within the houseboat occupants of California is solved. The plainfin midshipman fish that dwells in Pacific coastal waters from Alaska to Baja California court attracts females during breeding season using a nocturnal love song with an otherworldly sound that can be heard at night.
Males migrate during the late spring and summer from deep offshore sites into shallow intertidal waters, where they build nests beneath rocky shelters where they produce hums in the whole night by vibrating a gas-filled bladder within their abdomen to attract females to their nests to spawn. One hum is researched to last for almost two hours. Normally, neighboring males hum together in a chorus.
A United States research team led by Professor Andrew Bass said that the mystery was solved by keeping a small group of midshipman fish in constant darkness and the results were found that the fish hum in rhythm. Whereas, when placed in a constant light the fish humming was completely nil.
The midshipman fish was given with melatonin substitute and the fish continued to hum at random times of a day and it was noticed that the hum was without rhythm. The whole research study reveals that the fish has a low-frequency hum which is controlled by melatonin and internal clock based on light.
The plainfin midshipman fish grows up to 38 centimeters or 15 inches long, with olive-brown color. The name of the fish is depicted when the researchers found that the fish's underside contained rows of bioluminescent organs which look similar to the buttons on the uniform of a midshipman.
Dr. Ni Feng of Yale University, one of the researchers of the study said that melatonin which governs sleep and wake cycles in humans, features the nocturnal singing of the midshipman fish. According to BBC, the mystery of singing midshipman fish started in 1980's within the houseboat residents of Sausalito Bay, California. The residents wondered that the sound might be from the pumps of sewage plants, underwater power line, some secret experiment by the Navy or might be from extraterrestrials.
