Some Mushrooms Glow, and Here's Why

About 2,300 years ago, the Greek philosopher and scientist Aristotle noticed what he called a "cold fire" emanating from decaying wood in a forest. That may have been the first documented observation of bioluminescence in mushrooms, a phenomenon that's been observed over the years in 71 different species of the fungi.

The chemical process by which mushrooms generate light is still mysterious, but for years, scientists have puzzled over something else as well. Why do some mushrooms glow? What advantage does it provide to them?

A just-published study by U.S. and Brazilian researchers in the journal Current Biology finally provides a good answer. Basically, these mushrooms turn themselves into a natural version of the neon sign in the local bar and grill, in order to attract insect visitors –-beetles, flies, wasps and ants -– who will spread the fungal spores around and further the species' effort to reproduce and survive.

NEWS: Sea Worm Emits Strange Glow

"It appears that fungi make light so they are noticed by insects who can help the fungus colonize new habitats," says Cassius Stevani of Brazil's Instituto de Química-Universidade de São Paulo.

Additionally, the researchers found that mushrooms don't just give off light indiscriminately. Instead, their bioluminescence is controlled by a temperature-controlled circadian clock, which enables them to conserve energy by only turning on when it is dark enough for insects to spot them.

The researchers studied Neonothopanus gardneri, one of the biggest and brightest of bioluminescent mushrooms, which attaches itself to the base of young palm trees in coconut forests in Brazil.

PHOTOS: Magic Mushrooms in Your Yard

In order to figure out the function of the green glow given off by N. gardneri, researchers ingeniously fashioned fake mushrooms out of acrylic resin and lit some of them on the inside with LED lights, and then placed them in the forest. They found that the light-emitting fake mushrooms were more likely to attract insects.

Understanding mushrooms such as N. gardneri is important because of the role that they play in the forest ecosystem. "Without them, cellulose would be stuck in its form, which would impact the whole carbon cycle on Earth," Stevani said. "I dare to say that life on Earth depends on organisms like these."

Researchers discovered that

Fireflies

March 23, 2012 -

Humans may figuratively glow from within, but many species literally emit a natural glow. Here, we celebrate just some of these flashy organisms, such as these fireflies. Photographer Tsuneaki Hiramatsu used slow–shutter speed photos to produce images like this one of firefly signals. "These images show a selection of many extraordinary organisms that produce light, in conjunction with the American Museum of Natural History's upcoming Creatures of Light: Nature’s Bioluminescence exhibition," curator John Sparks of the museum’s Department of Ichthyology, told Discovery News. Bioluminescence refers to organisms that "generate light through a chemical reaction."

Bitter Oyster Mushrooms It’s a little known fact that some common mushrooms glow in the dark. These bitter oyster mushrooms (Panellus stipticus) are bioluminescent. They grow on decaying wood in the forests of eastern North America.

PHOTOS: Magic Mushrooms in my Yard

Dinoflagellates The flickering glow in this photo comes from thousands of live single-celled organisms called dinoflagellates. The species seen here, Pyrocystis fusiformis, is a spindle-shaped cell about one millimeter long -- just large enough to be seen without a microscope, according to Sparks. Tiny particles in each cell, called scintillons, contain chemicals that mix and make light when the water is shaken or stirred.

NEWS: Crocodile Turns Bright Orange

Bloody Bay Wall This interactive mural captures a slice of life on Bloody Bay Wall, off Little Cayman Island in the Caribbean Sea. In daylight, creatures on this coral wall can be seen in fine detail. To most observers, this scene might look quite normal, but it takes on an eerie glow at night. Sparks said, "Rare among organisms that live on land, the ability to glow is much more common in the ocean, where up to 90 percent of animals at depths below 700 meters are bioluminescent, including many unknown to science."

Green Fluorescent Protein The brilliant patches of green here come from a compound known as "green fluorescent protein" emitted from certain corals, fishes and sea anemones. The vivid colors only appear when the animals are illuminated by specific wavelengths of light.

NEWS: Glow in the Dark Surf Explained

If a different wavelength of light illuminates the same scene, glowing red hues emerge. Orange is yet another color that some glowing organisms can emit. "Like the crystal jelly, whose glow led to a revolution in cellular biology, these animals may hold important clues to essential questions regarding signaling mechanisms, sexual selection, and diversification in the deep sea," Sparks said.

NEWS: Phosphorescent Feline Fights AIDS

Scorpions Some scorpions, such as the one seen here, are fluorescent. Certain spiders, insects and minerals glow too. Sparks explained that the luminescent minerals contain fluorescent molecules that glow under ultraviolet light. Andrew Parker, research leader of the Department of Zoology at London’s Natural History Museum, explained that as soon as certain organisms evolved the ability to see, color, light, fluorescence and more all gained greater importance.

NEWS: Glowing Shark Wears Cloak of Invisibility

“Since vision evolved, everything has been fully adapted to the presence of a retina, adapted in terms of their color, shape and behavior,” Parker, author of the related book In the Blink of an Eye, told Discovery News. “Prior to the first highly mobile predator with vision, i.e. one that could have an affect on all other cohabitants, the rules would have been much different, and indeed we know from fossils that animal forms and ecology were much different.”

Black Dragonfish The female black dragonfish has a luminous lip that may be used to attract prey. The poor victims would then be chomped to death by the fish’s big, sharp teeth. Both males and females also have tiny light-emitting photophores scattered over their bodies, with larger photophores along the side. Rui Coelho, a shark researcher at the University of Algarve, Portugal, has studied bioluminescent marine animals. He told Discovery News that "photophores may be used to allow individuals to escape from predators or for species recognition, such as during the mating season."

Lanternfish The appropriately named lanternfish conspicuously uses bioluminescence in its ocean habitat. Although virtually all fish are at risk now, due to bycatch threats, pollution and other problems, laternfish account for approximately 65 percent of all deep sea fish, based on ocean trawling counts.

PHOTOS: Top 40 Nature Photos of All Time

Danaphos Danaphos is the name of an oceanic ray-finned fish genus. Its more common name is "bottlelights." It, and so many other species, both on land and in the sea, are under threat now. Sparks shared that "scientists are in a race against time as habitats are increasingly threatened by pollution, overfishing, and global climate change." You can, however, non-invasively admire Danaphos and the other glowing species at the new AMNH exhibit, which opens March 31 in New York and runs until Jan. 6, 2013.

NEWS: Glow In the Dark Species Found