What Is Bioluminescence and Why Do So Many Deep-Sea Animals Have It?

bioluminescence, bioluminescent ocean waves, bioluminescent waves, bioluminescent plankton
Bioluminescent ocean waves Photo credit: Phil Gibbs on Visualhunt.com / CC BY-NC-ND

What is bioluminescence?


Bio = biological, or life, Lumen = light (unit)
Bioluminescence is the biochemical emission of light by living organisms such as deep-sea fishes. It produces the “glow-in-the-dark” look of certain animals such as fireflies and the “fireworks” show when plankton are disturbed in the ocean(see photo of bioluminescent ocean waves).

What percentage of animals in the deep-sea are bioluminescent?


90% of animals in the deep-sea (below 1,640 feet or 500 meters) are bioluminescent (according to NOAA [National Oceanic and Atmospheric Administration]).

How do animals and plants produce bioluminescence?


Two chemicals are mixed together with oxygen and the reaction produces light. The chemicals are luciferin and luciferase and together they produce oxyluciferan.

Bioluminescence is made up of what colors?


Mainly blue-green as red is absorbed the further you go down in the ocean. There are species that emit infrared and red light and one group of organisms that produce yellow light.
from Causes of Color website

What kinds of ocean animals are bioluminescent?


Bioluminescent ocean organisms include bacteria, jellyfish, starfish, clams, worms, crustaceans, squid, fish, sharks and more to be discovered! (list according to NOAA)

Why are animals bioluminescent?


Animals are bioluminescent for protection as the light will scare some predators away. The vampire squid has bioluminescent mucus that they eject (like ink) towards predators. Animals can use bioluminescence to find mates (which is hard when in the dark, deep sea with no other light). They also can use it to find food (like Dory in Finding Nemo being drawn to the anglerfish lure. Fortunately Dory wasn’t eaten!). Also it can be used in communication, and for illumination.

What questions do you have about bioluminescence? Leave a comment below.