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Bioluminescent Organisms


Ankita loves to explore various aspects of science and is passionate about writing on topics of her interest.

We have always been fascinated by fireflies. Watching the fireflies glow in the dark makes us wonder about their creation.

Bioluminescence is the term used to describe the light-producing capability of an organism. In other words, the emission of light by a living organism is known as bioluminescence. Bioluminescence occurs due to certain chemical reactions within the organism. The chemical reactions which produce light are known as chemiluminescence and the living organisms exhibiting chemiluminescence are known as bioluminescent organisms.

The organisms capable of bioluminescence are mostly found in the ocean. Only a few of them are found in the land. Chemiluminescence occurs when luciferin, a polycyclic light-emitting compound, reacts with either luciferase or photo proteins.

Organisms can control their light-emitting capabilities and only glows when it is important like feeding, protection, mating, or releasing extra energy from their body. Most interestingly, the bioluminescent organisms can choose the color and the intensity of the light they produce.

Bioluminescence in Dinoflagellates

Bioluminescence in Dinoflagellates

Foxfire bioluminescent mushroom

Foxfire bioluminescent mushroom

Bioluminescence in Different Organisms

Fungi: More than 80 species of fungi are capable of bioluminescence. Most of them occur in tropical forests and a few are found in temperate forests. Foxfire, the bioluminescence created by some of the species of fungi (like mushrooms) present in decaying wood, is found in temperate forests. Several theories have been put up by scientists as to why bioluminescence is exhibited by fungi. Some of them say it is to attract insects at night to carry out pollination by transferring the spores to different locations. Others say constant light emission occurs to release extra energy as a result of metabolic reactions.

Plants: True plants rarely show bioluminescence. Nowadays, bioluminescent plants are artificially produced by crossing with bioluminescent bacteria. However, there are some pseudo plant species that exhibit bioluminescence. For example, Dinoflagellates, which are found in the ocean, belong to the kingdom Protista but are considered to be pseudo plants. This is because they are able to produce their own food through photosynthesis. With over 18 genera capable of bioluminescence, most of the Dinoflagellates emit blue-green light. The emission is rarely scrutinized and can only be found in tropical lagoons.

Bacteria: Often found in the ocean, bioluminescent bacteria may be free-living or can occur in symbiotic relations. For instance, Angler fish, found in greater depths in the ocean have bioluminescent bacteria in a light-emitting rod which helps to attract prey. In return, the Angler fish provides a safe place for the bacteria to live within them. Most of the luminous bacteria are parasitic. The free-living luminous bacteria in the ocean are often found in the skin or gut of most marine animals. They live there as non-specific parasites. The three major genera in which most of the bioluminescent bacteria are found are Vibrio, Photobacterium, and Photorhabdus. Marine species belong to the genera Vibrio and Photobacterium whereas terrestrial species belong to Photorhabdus.

Deep sea Angler fish exhibiting bioluminescence

Deep sea Angler fish exhibiting bioluminescence

Bioluminescent bacteria

Bioluminescent bacteria

Need for Bioluminescence

There are different reasons for emitting light by the bioluminescent organisms. Some of them are described below:

Feeding: Organisms attract their prey by glowing themselves and hence use this power to feed themselves. For example, the Angler fish have bioluminescent bacteria in a light-emitting rod that attracts prey. Some organisms also emit bright lights to light up the surrounding area to search for nearby prey.

Attract mates: Bioluminescence is also used to attract mates in order to fertilize. A tiny crustacean, Caribbean ostracod, attracts its female counterpart by lighting its upper lip. The ability to glow also helps in distinguishing male from the female of certain organisms. For instance, studies have found that Angler fish, Ponyfish, and Flashlight fish emit light to differentiate between the males and the females and also communicate in order to mate.

Protection: The glowing capacity of certain organisms protects them from predators. The predators go blind and lose their prey due to a sudden bright emission of light and thus this helps the prey escape.

Studying the bioluminescent organisms and their activities can be really interesting. People can visualize different art forms in the beautiful lights emitted by these creatures. Newer discoveries of the ocean have been carried out by studying the bioluminescent organisms.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.


Ankita B (author) on January 11, 2020:

Thank you. I am glad.

Umesh Chandra Bhatt from Kharghar, Navi Mumbai, India on January 10, 2020:

Nice article. Well explained. Thanks for posting.