Newly-discovered fluorescent polyps light up sea snails in Red Sea

FEBRUARY 8, 2016

by John Hopton

Marine creatures that give off a beautiful glow have been discovered in coral reefs south of the Red Sea, according to a new report.

Russian biologists who found the molluscs in waters off Saudi Arabia noted that a localized glow in certain parts of the body can help to distinguish different species of organisms that have identical structure. The light is kindly donated to the gastropods by hydrae, and unlike similar lifeforms these Red Sea "fluorescent lanterns" spread colonies and decorate the shells of Nassarius snails with coats of green lights that resemble Christmas tree decorations.

"Sea hydroids, unlike hydrae, are often found in colonies and can branch off tiny jellyfish," said Vyacheslav Ivanenko, one of the authors of the research and the leading researcher of the Department of Invertebrate Zoology of the Lomonosov Moscow State University. "The unusual green glow of these hydrozoas (presumably, a new species of the genus Cytaeis, whose body length reaches 1.5 mm) was revealed in the peristomal area of the body".

Having been buried in the sand during the day, the creatures tend to be active at night, which sort of makes sense because it gives them a chance to show off, but at the same time one might wonder if their impressive glow might hinder their hunt for food. Quite the opposite may be true, according to the researchers, who suggest that the light my actually attract prey. Intriguingly, though, the exact reason for the lumiousity is unknown. The extent to which the hydrae are fussy about choosing their hosts is also as yet unclear.

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