Fluorescence is widespread in fish, study finds
By James Gorman From NY Times
From sea horses that glow red to bright green eels, researchers have discovered 180 species of fish that fluoresce under blue light.
It was the green eel that did it. Scientists from the American Museum of Natural History had been exploring a reef off Little Cayman Island, investigating fluorescent coral and gathering photos for an exhibition.
In reviewing images taken during the team’s dives, the researchers spotted a glowing, apparently fluorescent, green eel.
So began four more expeditions to the Bahamas and the Solomon Islands with scuba divers and submersibles, leading to the discovery that biofluorescence is actually widespread in fish, present in at least 180 species and 16 orders.
The findings, reported in the journal PLoS One on Wednesday, have implications for the evolution and behavior of these fishes. They may also provide new chemicals for laboratory research, according to the authors, including John S. Sparks of the American Museum of Natural History and David Gruber of the museum and the City University of New York.
Bioluminescent organisms like fish and fireflies produce their own light. Biofluorescent fish and corals do something different, absorbing blue light, which is relatively high-energy, and transforming it into relatively lower green, orange and red light. Some organisms do both.
The proteins involved in fluorescence are prized by researchers, who adapt them to light up different biological processes. In 2008 the Nobel Prize was awarded to three scientists for the discovery in jellyfish, and adaptation for research, of what is usually called G.F.P., for green fluorescent protein.
The findings also have evolutionary significance, as the authors of the paper point out.
Most of the fish species they identified are camouflaged, so they are usually nearly invisible, at least to humans. But they need to find each other, including during mating. The researchers say they think that these species can probably see fluorescence easily.
Human divers can see it, but not very well unless they shine an intense blue light on the organisms, producing higher levels of fluorescence, as the divers did on the reef off Little Cayman.
The traveling exhibit they were working on at the time, “Creatures of Light: Nature’s Bioluminescence,” will open in May at the Canadian Museum of Nature in Ottawa. It ended its run in New York at the American Museum of Natural History in 2013.
For more on this story and to view the video go to:
PHOTOS: NY Times & Redorbit & news. sciencemag
