A newly discovered species of polyps illuminate the Red Sea, forming small colonies on the shells of sea snails.
An international team of researchers in Russia probed the nature of the fluorescent sea creatures, which put out green “fluorescent lanterns” across the shell of the Nassarius margaritifer. They found the luminous polyps while studying coral reefs on the Farasan archipelago in Saudi Arabia, south of the Red Sea.
While exhibiting similar characteristics, the marine creatures are only distant relatives of fluorescent polyp hydrae, located in fresh water.
And unlike the fresh-water creatures that lead a solitary life, these newly found polyps in the Red Sea spread colonies embellishing small sea snail shells with streaks of green light.
"Sea hydroids, unlike hydrae, are often found in colonies and can branch off tiny jellyfish," reports study author Vyacheslav Ivanenko of Lomonosov Moscow State University.
The researchers have not yet confirmed or named the newly discovered species, but thought it instrumental in improving the future classification of hydroids.
The hydrozoas, added Ivanenko, emit a unique green glow in their body’s peristomal area or around the mouth. They are presumed to be a new species from the genus Cytaeis, whose body can measure as long as 1.5 millimeters.
The researchers speculated that the mysterious glow around their mouths could be intended for attracting prey. Fluorescent flashlights may appear visible to other invertebrates at sunset and sunrise and in the moonlight.
Yet the role of such glow is poorly explored, raising questions on how these polyps choose their host or how the luminescence vary from one hydrozoa species to another.
Fluorescence – or glow of proteins when illuminated by light – is prevalent in corals Anthozoa and hydroid jellyfishes, as well as in some lancelets and combjellies. In hydrozoa, fluorescence has been investigated only in six species and usually on the stalk or tentacles, not around the mouth.
The team noted that differentiating where the glow emanates in the body of these different polyps can help differentiate one species from another.
The findings were published in the journal PLOS One.
