Please Explain: Bioluminescence

John Sparks, associate curator and curator-in-charge, department of Ichthyology at the American Museum of Natural History, and David Gruber, assistant professor at the City University of New York and a research associate at the museum, discuss the variety of bioluminescent organisms—from fungus to dinoflagellates to jellyfish—and explain the various ways they glow, the functions of bioluminescence, and how scientists study it. The exhibition Creatures of Light: Nature’s Bioluminescence is on view at the American Museum of Natural History through January 6, 2013.

Bitter oyster mushroom (<em>Panellus stipticus</em>)
Bitter oyster mushroom (Panellus stipticus)

These bioluminescent mushrooms grow on decaying wood in the forests of eastern North America.

( © AMNH\J. Sparks )
Live dinoflagellates (<em>Pyrocystis fusiformis</em>)
Live dinoflagellates (Pyrocystis fusiformis)

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

( ©AMNH\D. Finnin )
Bloody Bay Wall close up image 1 (full-spectrum illumination)
Bloody Bay Wall close up image 1 (full-spectrum illumination)

Cayman Islands’ Bloody Bay Wall, a species-rich coral wall that is home to many bioluminescent and biofluorescent animals. Still relatively pristine, Bloody Bay Wall drops down 1,000 feet.

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. The same areas look very different at night, when lit by high-energy spotlights. The brilliant patches of red, green, and orange come from corals, fishes, and sea anemones that are fluorescent, not bioluminescent. The vivid colors only appear when the animals are illuminated by specific wavelengths of light.

( © Jim Hellemn, portraitofacoralreef.com )
Bloody Bay Wall close up 2 (fluorescence image showing red fluorescence and Green Fluorescent Protein (GFP))
Bloody Bay Wall close up 2 (fluorescence image showing red fluorescence and Green Fluorescent Protein (GFP))

Cayman Islands’ Bloody Bay Wall, a species-rich coral wall that is home to many bioluminescent and biofluorescent animals. Still relatively pristine, Bloody Bay Wall drops down 1,000 feet.

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. The same areas look very different at night, when lit by high-energy spotlights. The brilliant patches of red, green, and orange come from corals, fishes, and sea anemones that are fluorescent, not bioluminescent. The vivid colors only appear when the animals are illuminated by specific wavelengths of light.

( © Jim Hellemn, portraitofacoralreef.com )
Bloody Bay Wall close up 3 (coral fluorescence image showing GFP)
Bloody Bay Wall close up 3 (coral fluorescence image showing GFP)

Cayman Islands’ Bloody Bay Wall, a species-rich coral wall that is home to many bioluminescent and biofluorescent animals. Still relatively pristine, Bloody Bay Wall drops down 1,000 feet.

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. The same areas look very different at night, when lit by high-energy spotlights. The brilliant patches of red, green, and orange come from corals, fishes, and sea anemones that are fluorescent, not bioluminescent. The vivid colors only appear when the animals are illuminated by specific wavelengths of light.

( © Jim Hellemn, portraitofacoralreef.com )
Scorpions
Scorpions

Minerals can contain fluorescent molecules that glow under ultraviolet light. Scorpions, some spiders, and many insects are fluorescent too.

( ©AMNH\D. Finnin )
Flashlight fish (<em>Anomalops katoptron</em>)
Flashlight fish (Anomalops katoptron)

Live flashlight fish are on display in the exhibition. Flashlight fish harbor bioluminescent bacteria in an organ under their eyes and use the light produced by the bacteria to communicate, avoid predation, and to attract prey.

( © FMNH\L. Smith and AMNH\J. Sparks )
of