Fireflies of the Sea
Have you ever seen a firefly? It glows due to something called bioluminescence. Our oceans are full of creatures that use bioluminescence. Why are these creatures glowing? There are actually many different reasons why they glow or flash. They could be calling for help or trying to attract a meal – they might even be trying to lose a predator. Different creatures use bioluminescence in different ways; squids spray bioluminescent ink, whereas other creatures have bioluminescent cells the glow or flash.
There are many different types of animals that glow and for all different reasons. For example, the deep sea angler fish has a small rod above its mouth with a “lightbulb” to attract fish near its mouth so it can eat them. There’s also the vampire squid that shoots out a glowing liquid when escaping a predator to shock it. As a last resort, the deep sea jellyfish flashes when it’s attacked, it does this to call larger predators in hopes they will eat it’s attacker.
Bioluminescence is created by a chemical reaction. This reaction involves at least three ingredients: an enzyme called luciferase, oxygen, and luciferin. The luciferase helps the oxygen bind to the organic molecule called luciferin. The high-energy molecule created by the reaction releases energy in the form of light. To be able to do this it took 50 evolutions or more!
Bioluminescent are found throughout marine habitats, they can be found in the deepest parts of the ocean all the way to the surface. There are so many more types of these creatures that have not been discovered yet. Humans have only explored 5 percent of our oceans and have barely touched the deepest parts. Scientists discover new fish everyday and there are thousand or even millions more to be found.
Click here for a link to lesson plans and activities on bioluminescence.