Since
the invention of the incandescent light bulb by Thomas Alva Edison in
1879, or at least that’s what we’re all made to think considering the
fact that some historians believe that there were over 20 inventors of
incandescent lamps before Edison made his own, artificial lighting has
really gone a long way in improving the quality of our lives. Well, long
before that happened, some amazing creatures have already devised
really cool mechanisms to light up the animal kingdom.
Bioluminescence
is the ability of living things to emit light. For a vast array of
reasons, which include but not limited to survival, defence, or merely
just showing off; these creatures emit light via really complicated
chemical reactions occurring within special cells and these reactions
lead to the emission of light as a product. In this post, we’re going to
learn about ten of these amazing creatures and the mechanisms they use
to produce light energy and glow in the dark.
Below are Ten (10) animals that emit light energy and glow in the dark.
1. You guessed it, Fireflies:
Everyone
loves Fireflies and they love us too, I think. The beautiful flashing
light they emit in the dark is hard to ignore. They’re even commonly
depicted in almost every cartoon you see on TV. It is important to note
that there are over 2,000 species of Fireflies around the world. In
fact, they’re the only creatures with the name ‘Fly’ that I can tolerate. Funny enough, these guys aren’t actually Flies. They belong to the family Lampyridae (which are a family of Beetles), hence, they’re commonly called winged Beetles.
These
guys glow in the dark to attract their mates or prey creating colours
which may be green, yellow or pale red. So how do they do this?
Bioluminescence is possible in Fireflies thanks to a chemical reaction
that occurs in special organs on the lower abdomen of the Firefly. This
organ contains an enzyme called Luciferase and
this enzyme acts on Luciferin (a light-emitting compound found in many
Fireflies) in the presence of Oxygen, Magnesium ions and the energy from
the hydrolysis of high-energy bonds in ATP. The overall reaction
produces light as a by-product making these creatures glow in the dark.
2. Glow-worms:
These
are commonly found in New Zealand and Australia especially in the
famous Waitomo caves on the North Island of New Zealand which has grown
to be an attraction for Tourists from all over the world. Glow-worms are
actually the Larvae of a species of Fly known as Fungus gnat. These
Larvae burn off waste and attract food with the light energy they emit
via bioluminescence while they mature in the favourable conditions
provided by the caves.
Waitamo Glow-worm Caves are a must see for any traveller because it really is amazing how these worms glow in the dark.
3. The Anglerfish:
The
Ocean is full of diverse and really crafty predators. Many of which
have evolved certain features that make attracting prey quite easy and
that’s where the Anglerfish comes in. The first time I saw this guy was
in Finding Nemo and it’s not a pretty looking fish. The Anglerfish has a fleshy growth from its head called the Esca or Illicium which
glows in the dark and Just like many women in the world we live in,
some fishes in the ocean are attracted to shiny things and they swim
towards the light only to find the Anglerfish waiting in the dark. So
the Anglerfish uses this to its own advantage. Really clever isn’t it?
4. Smalleye Pygmy Sharks:
As
the name implies, ‘Pygmy sharks’ are one of the smallest Sharks in the
world with adults measuring not more than 8.7inches (22 centimetres).
Nevertheless, these sharks have evolved a mechanism that allows them to
glow in the dark. It inhabits the open Ocean using its blue shining
belly as camouflage. Many scientists claim that these sharks have
special light-emitting organs called Photophores.
This
blue-light camouflage works perfectly for the Pygmy sharks making them
somewhat invincible to predators stalking them from far below the ocean
surface because once you dive into the ocean and look up, the entire
ocean looks blue and the Pygmy Shark’s bioluminescence allows it to
blend perfectly with its surroundings.
5. Bobtail squids:
One
very unique sea creature is the Bobtail squid and they inhabit the
shallow coastal waters of the Pacific Ocean and the Indian Ocean. Only
just about the size of my thumb, this animal houses bioluminescent
bacteria in special cells producing light energy. They use this light to
protect themselves from predators. They can manipulate the light
emitted by these bacteria controlling the direction and brightness of
their glow. They spend the day hiding in the ocean floor and emerge only
at night showcasing their amazing colours and using the light to
navigate the dark in search of food. Just a side note, these animals are
quite intelligent with their brain size bigger than you’ll actually
expect from a creature this tiny.
6. Scorpions:
You
may never have noticed this, but scorpions actually do glow in the
dark. Well, unlike their other bioluminescent colleagues, they do not
produce their own light. If you feel like seeing this for yourself,
Scorpions aren’t really difficult to find. When you see one, switch on
an ultraviolet lamp and watch the Scorpion glow a vibrant blue-green
colour. Beautiful isn’t it? Not… I hate Scorpions and the fact that they
glow makes them even weirder.
The
reason why Scorpions glow is not really clear. Scorpions come out from
their hiding places to hunt for food at night under the moonlight. The
weak amounts of Ultraviolet radiation cause these creatures to glow in
the moonlight. We can’t actually say their glow attracts small insects
to them because there’s nothing scarier to these insects than a Scorpion
that glows and wants to eat you. Their glow is as a result of the way
the proteins in the exoskeleton of the Scorpion are arranged and the
colour may serve as a form of identification between them. Whatever the
reason for their glow, it’s still amazing to watch.
7. The Firefly Squid:
This
squid gets its name from the flashing lights that resemble those of the
Firefly. It is a member of the Cephalopod family which many other
Squids belong and it is very popular in Japan because every year,
millions of these tiny glowing creatures gather to spawn in the western
Pacific Ocean and form what I like to call 'bioluminescent beach'. Growing to a length of about three inches, the Firefly Squid is one of the smallest Squids in the Oceans.
It
possesses special light-producing organs called Photophores which are
found in many parts of its body including the tips of its tentacles and
around the eyes emitting a deep-blue light. Like the other
bioluminescent creatures, the Firefly Squid has the ability to control
its glow allowing it to confuse predators and attract prey. Most
importantly, the Firefly Squid is believed to be the only member of the
Squid family to possess coloured vision. So, these guys can actually
enjoy their own light show.
8. The Black Dragonfish:
This
amazing deep-sea creature uses bioluminescence to navigate the dark
waters in search of prey. It is a rather strange-looking, long and
slender fish with long fang-like teeth and it is found at depths of
between 5000-8000 feets in the world's Oceans. What makes this creature
very interesting is that they can produce light in the red/infrared
range which many animals cannot perceive and also light in the
blue/green range.
Hence,
it uses infrared to its advantage to provide light for itself in the
dark. Also possessing special light-emitting organs called photophores
that cover the lower and upper surfaces of the animal and even beneath
the eyes.
9. The Jellyfish:
There’s
no way we’ll talk about bioluminescence and leave out our jelly-like
friends. Many species of Jellyfish are masters of bioluminescence. They use
their ability to glow to surprise or frighten away predators. This
works because the long tentacles of the jellyfish coupled with the light
they emit make them appear larger than they are to potential predators.
Some jellyfish drop their tentacles as a form of distraction that can
confuse predators. Predators are typically attracted by the light of the
falling tentacles and focus their attention on it instead of the
jellyfish's body, which gives the jellyfish the chance to escape.
Different species of Jellyfish glow differently producing different
colours and it's really beautiful to watch.
10. The Flashlight Fish:
Funny
name for a creature but this fish uses Bioluminescent organs under its
eyes to communicate, attract prey and confuse predators. Flashlight
fish are a rarely spotted; they are nocturnal, spending daylight hours
tucked into deep-water caves and crevices. The light that a flashlight
fish emits can be seen from over 100 feet (30m) away! Zooplankton is
drawn to the glowing ‘eyes’ of a flashlight fish. Not only will the
flashlight fish eat the zooplankton, it will also wait and consume all
the small fish that come near to feed on the illuminated zooplankton.
Their symbiotic bacteria are constantly producing the light-emitting
chemical reaction but flashlight fish are able to rotate the photophore
downward, covering the light. They use this mechanism to evade predators
but shutting the light off or confusing a pursuing predator by blinking
the light while swimming in a zig-zag pattern to confuse the predator.
There you have it, ten animals that glow in the dark, lighting up the animal kingdom. There is a technique called Bioluminescence imaging (BLI) that is used to study ongoing biological processes in small laboratory animals. Bioluminescence imaging (BLI)
is a technology that was developed to allow the noninvasive study of
biological processes occurring in small animals who voluntarily offered
themselves for testing (probably not). For whatever reason,
bioluminescence really is amazing. Thanks for reading, endeavour to
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take a minute. If I’m forgetting something, please don’t hesitate to
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