What is Bioluminescence?

In the branch of aquatic science, we are yet to discover so much, though the things we have already discovered are so fascinating, it’s amazing how nature still manages to surprise us! Bioluminescence? What does this giant word mean? Let’s see!

  • Etymology

What does etymology mean? Well, etymology means the origin of words through history. For eg. Probiotic word comes from Greek and Latin meaning ‘for life.’ This is used because, English composes of many different and ancient languages. So, the etymology of Bioluminescence comes from two Greek words, bios- which means living, and lumen- means light. 

  • Explanation

Okay! Now let’s get to our topic. Bioluminescence.Have you ever seen fireflies? That is some wonderful sight to see! But have you ever wondered what causes it to glow? Due to a certain kind of chemical reaction, makes the abdomens to glow. These are insects, but do you know the Bioluminescence in the oceans…?

Source: Pinterest

  • Ocean Bioluminescence

Many organisms living in the ocean have the property of bioluminescence. Bioluminescence can be found in bacteria ( living in the ocean), algae,jellyfish, worms,crustaceans(a sea animal), seastars, and some species of sharks. Mind you, these are comparatively just a few listed. For the organism to produce light, it must contain a compound called Luciferin – meaning light bearer in Latin. Now, when this compound(luciferin) comes in contact with oxygen, it reacts with the gas, converting into light energy. An organism must contain luciferin in order to become bioluminescent. There are many types and varieties of this  compound present in different creatures. But generally, most of the organisms produce luciferin catalysts. This sight is more prominent in the deep sea region but the most breathtaking scene is on the surface of the oceans when tiny micro organisms grow making it seem..just magical. According to a research ,  fishes of about 1500 known species have the ability to produce this light through luciferin. Bioluminescence are wonderful sights to look at. From the study of 2018, scientists discovered that the ray finned fishes have evolved about 27 on the basis of this property .Amazing,isn’t it?

Source: By Smit Patil from unsplash


Now, the question might come into your mind that ‘ what is the actual use of bioluminescence?’ Well, for us it might be just a great scene to look at but for the sea animals, it’s likely a vital property. 

  1. Prey- These animals use their light to lure their prey to come near them, making it easy and convinient to hunt. This technique can also fool larger animals.For example. The cookie cutter shark(weird name) attracts squids and sharks from its light and when they are close enough, it bites on them.
  2. Communicate- For the bioluminescent animals, they have to be safe from being eaten or getting hurt. So they use these methods, maybe to communicate.
  3. To attract mates- Females usually use bioluminescence to attract male species to come to them.(Pretty sneaky, aren’t they?)
  4. Protection- Animals can potentially hide themselves through the surface of ocean, when using bioluminescence.  It helps them to survive and make themselves invisible
  5. Confuse- Some species of squids splash bioluminescent liquid rather than ink, simply to confuse their predators.
  6.  Vision-  Many seaanimals live on the  lower surfaces of the ocean. Bioluminescence helps the organisms to see clearly.
  • Is it dangerous?

 No, not necessarily every bioluminescent organism is toxic. But yes, they do exist. The dinoflagellates  a microbe which is found in the Matsu islands of  Taiwan,China. The microbe is also called China’s ‘blue tears.’ It is because the organism has an eerie glow to it. Many tourists come here to observe this phenomenon . But these dinoflagellates  are toxic. But why? Well, dinoflagellates is an algae which is harmful to many sea organisms and humans as well. What makes them toxic is, when they eat, they release ammonia particles in the sea. Not only that, but also, they take up all the oxygen available for the atmosphere, leaving nothing for the other sea animals,hence causing them to die. And what is more disastrous,that their numbers are increasing by every year. It is also known as harmful algal blooms(HAB’s).Some say that it is romantic to look at, but I really wouldn’t  think choking myself to death as romantic..

A Hawaiian bobtail squid actually has an organ which is practically filled with bioluminescent bacteria just after hours of its birth. But it usually contains the chemicals needed within its body.

  • How many colours..?

We all know that light travels in the form of something called ‘wavelenghts’. Some wavelengths are short, whereas others are big. The visible spectrum of  light is VIBGYOR (violet, indigo,blue,green,yellow,red) and all the shades from the mixture of them. Light cannot travel in the deep sea as the wavelengths are unable to travel that far. Hence, most of the colours in bioluminescence are blue-green. Infact, only some animals living in the deep sea have the vision to see the colours of greater wavelength like red. 

Source:<span>Photo by <a href=”https://unsplash.com/@bigmck56?utm_source=unsplash&amp;utm_medium=referral&amp;utm_content=creditCopyText”>Trevor McKinnon</a> on <a href=”https://unsplash.com/s/photos/bioluminescence?utm_source=unsplash&amp;utm_medium=referral&amp;utm_content=creditCopyText“>Unsplash</a></span>

Bioluminescence is also used to solve the vast mysteries of den in the oceans. According to a site, Edie Widder- specialising in bioluminescence made some very mind boggling facts about squid etc.

This phenomenon is really beautiful and magnetic to see and can be spotted from even far away. Unfortunately, only some sea surfaces have the bioluminescent property, maybe due to some climatic conditions, or maybe they are everywhere, we just can’t see them !!

Categories: Science

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