Gallery: 8 Beautiful Bioluminescent Creatures From the Sea
01clusterwink-snail
While a handful of land animals can create their own light, homemade luminescence is the rule rather than the exception in the open ocean's dark waters. Researchers estimate that between 80 and 90 percent of deep-dwelling animals are bioluminous, creating light by mixing the pigment luciferin with luciferase, the enzyme that makes it glow. The light tends to green and blue, colors that travel far in seawater. Glowing helps attract mates, lure prey or confound predators. Many of these animals live thousands of meters deep and are difficult for scientists to find and study. Here are some of the prettiest — and strangest — glowing creatures of the seas. __Above:__ Clusterwink Snail ----------------- The clusterwink snail, recently described in the *Proceedings of the Royal Society B*, shines its light [through a magnifying shell](http://stag-komodo.wired.com/wiredscience/2010/12/glowing-snail-shell/), making itself look more imposing. *Image: Nerida Wilson/University of California, San Diego.*
02atolla
Atolla ------ This deep-sea dwelling jellyfish is known for its “burglar alarm.” When attacked, it sets off a brilliant [light display](http://www.youtube.com/watch?v=xjaNzZt2olk&feature=related) that can be seen for 300 feet. Researchers think the fireworks are intended to attract something even larger and fiercer. If the new predator takes an interest in the jelly’s attacker, it might be able to escape. *Image: [Steve Haddock](http://www.lifesci.ucsb.edu/%7Ebiolum/)/Monterey Bay Aquarium Research Institute.*
03abraliopsis-squid
Abraliopsis Squid ----------------- This squid has small light organs on the underside of its body for camouflage. It uses this illumination to blend in with the sky, hiding its silhouette from predators watching from below. *Image: [Steve Haddock](http://www.lifesci.ucsb.edu/%7Ebiolum/)/Monterey Bay Aquarium Research Institute.*
04tomopteris
Tomopteris ---------- This sea worm, a polychaete, is one of the few creatures that make yellow light. If disturbed, it can let loose glowing sparks from foot-like appendages called parapodia. In this picture you can also see its eggs, which will soon be released into the water. *Image: [Steve Haddock](http://www.lifesci.ucsb.edu/%7Ebiolum/)/Monterey Bay Aquarium Research Institute.*
(c) 2004 MBARI05vampire-squid
Vampire Squid ------------- Neither a true octopus nor a squid, the vampire squid doesn't have ink sacs — of little use in dark waters. When it's frightened, the vampire fires a gooey cloud of bioluminescent mucus, surprising attackers and giving it a chance to escape. Vampire squid also use photophores on their bodies' undersides to hide their outlines against the sky. *Image: [Steve Haddock](http://www.lifesci.ucsb.edu/%7Ebiolum/)/Monterey Bay Aquarium Research Institute.*
06colonial-jelly
Colonial jelly -------------- This kind of jellyfish, which can grow to about 12 inches, controls its elevation in the water with a gas-filled float. Gas is released through a pore in the bottom of its float, which is refilled through secretions from a special gland. Its luminescence is a mystery. Scientists think it startles predators, but it's just a best guess. *Image: [NOAA](http://oceanexplorer.noaa.gov/explorations/02arctic/background/fauna/fauna.html).*
07deiopea-comb-jelly
*Deiopea* Comb Jelly -------------------- Most comb jellies, like this 2-inch *Deiopea*, named for a mythological water nymph, are hermaphroditic. They release both eggs and sperm, which then meet and fertilize in the open water. Though it's possible for comb jellies to self-fertilize, researchers don’t know how often this happens. Like the siphonophore, comb-jelly luminescence isn't fully understood. It's thought to be defensive, but we don't know for sure. *Image: [Steve Haddock](http://www.lifesci.ucsb.edu/%7Ebiolum/)/Monterey Bay Aquarium Research Institute.*
08red-tide
Red Tide -------- The most common bioluminescent creatures are speck-sized, plant-like dinoflagellates whose blooms cause so-called red tides. They flash brilliant blue to scare off predators when they're disturbed or caught in a wave. See some of these creatures [in action](http://www.youtube.com/watch?v=XD7thJVRKmQ&feature=related). *Image: [catalano82](http://www.flickr.com/photos/piratelife/2947977752/)/flickr.*
