SmithsonianMag.com – Most land dwellers are familiar with bioluminescence only in the context of fireflies. But this natural phenomenon is much more widespread than those winged wonders let on. The vast majority of bioluminescent creatures on the planet are actually found in the ocean, ranging from bacteria to jellyfish to sharks.
But while scientists knew that many fishes are bioluminescent, they could only guess at just how common light production is among those animals. Now, new research reveals surprising results: up to 80 percent of ray-finned fishes living in the open water—from deep-sea-dwelling anglerfish to coral-reef-residing flashlight fish—make their own light. What’s more, the phenomenon has evolved independently in that group 27 times. As the researchers report in PLOS ONE, this unexpectedly high prevalence implies that, for fishes, producing their own light is more than just a neat trick—it must also come with significant advantages.
“The fact that bioluminescence evolved so many times indicates that it serves some strong biological importance,” says Matthew Davis, a biologist at St. Cloud State University in Minnesota who led the study. “We also think that repeated evolution of bioluminescence was critical to species diversification [in] deep-sea and midwater environments.”
Read more: http://www.smithsonianmag.com/science-nature/way-more-fish-can-make-their-own-light-we-thought-180959346/?no-ist
