Daily Update 3.8
Week 6: Module 3: Date 3/8/13
What is Bioluminescence? Bioluminescence is the creation of light through a chemical reaction that takes place within the organism.
Fireflies and glowworms are popular terrestrial organisms that produce bioluminescence. There are numerous marine examples of bioluminescence, including fish and many invertebrates, including coral, pictured below. Most of the squid species use some sort of bioluminescence as well.
Bioluminescence has many uses in the marine environment. Many species use it as a defensive mechanism. For example some squid species will match the light of the organisms below in order to hide from predators. Others such as the dinoflagellates, a type of plankton, use it to illuminate a predator making it more vulnerable to larger predators. Still other squid species expel a bioluminescent mixture to distract a predator while the squid makes its escape.
A number of predators also use bioluminescence. The anglerfish, made famous by the movie Finding Nemo, use it to attract prey. The cookiecutter shark has a blank patch in its bioluminescence that resembles a small fish, which lures in larger fish for the shark to attack.
When bioluminescence is observed en masse in the ocean it is most often caused by dinoflagellates.
These dinoflagellates are marine plankton and have an important role in the food chain. This plankton contains many different species, some of which cause the ‘red tides’. Half of the species of dinoflagellates practice photosynthesis and not all of them are bioluminescent. There are around 20 species that do produce bioluminescence. Almost all bioluminescence is in the blue spectrum because blue light transmits best in water. Have any of you experienced bioluminescence? If you have we would love to hear about it!