Fireflies or lightning bugs are nocturnal beetles comprising the family Lampyridae. There are about 2,000 extant species of firefly.
Everyone knows how fireflies got their name, but many people don't know how the insects produce their signature glow. The answer is that fireflies have dedicated light organs situated below their abdomens. As oxygen enters into the abdomen, it combine with an organic compound called luciferin. A chemical reaction takes place and gives off the familiar yellow-green glow of a firefly.
This spectacular Glow-in-the-Dark insect can regulate the airflow into the abdomen producing a blinking pattern. Fireflies use their glow to attract mates.
2. Antarctic Krill
Do Antarctic krill really glow in the dark at sea? How do they do this?
Yes, Antarctic krill (Euphausia superba) often referred to as light-shrimp really do glow in the dark. They have photophores ("light spots") along their sides, their ventral surface (facing downward), and beneath their eyes. These photophores produce a blueish-purple light using a special chemical reaction common to many light producing animals.
3. Green Bomber Worm
Thousands of feet beneath the sea live segmented worms that can release green glowing body parts! This kind of glow-in-the-dark ability is called bioluminescence. In 2009, scientists found a new kind of glowing animal, a swimming worm. They call it a Green bomber worm (Swima bombiviridis).
To escape from predators, the "swimming green bomb" release little balloons of skin filled with a fluid that glows green. The glowing skin distracts predators, which allows the green bombers to swim away.
4. Crystal Jelly
The Crystal jelly (Aequorea Victoria) is a brightly luminescent jelly, with glowing points around the margin of the umbrella. When disturbed or threatened, it emits give a green-blue glow under special lighting because of more than 100 tiny, light-producing organs surrounding their outer bell. This emission of light comes from its ability to release calcium (Ca2) very quickly, which interacts with the photoprotein aequorin. Crystal jelly is able to glow in order to send a threat to its enemies. However, this jellyfish does not glow if it is not underwater.
Scorpions are known to glow a vibrant neon blue when exposed to ultraviolet (‘black’) light. This transformation is due to the presence of several chemicals, including beta-carboline, that cause it to glow under UV light. Scientists still can't figure out the reasons why scorpions glow. Perhaps to lure their prey, byproducts of normal chemical reactions or to attract mates. one thing is sure, scorpions lose this ability temporarily when they shed their skins, but gradually regain it after their molts.
6. New Zealand Glowworm
The New Zealand glowworms (Arachnocampa luminosa) are the larvae (maggots) of a special kind of fly known as a fungus gnat. They are found found only in the dark and damp areas of New Zealand, particularly the Waitomo Caves. The species construct a glowing canopy or a snare of sticky threads as they hang down to the ceilings or walls of caves. As night descends, they glow a radiant blue color to lure unsuspecting prey.
The glow-worm’s tail-light shines from an organ which is the equivalent of a human kidney. All insects have this organ but the glow-worm has a unique ability to produce a blue-green light from it.
The chemical reaction that produces the light consumes a lot of oxygen. An airbag surrounds the light organ, providing it with oxygen and acting as a silvery reflector to concentrate the light. The New Zealand glowworm can glow at all stages of its life cycle (except as an egg), but the larva has the brightest light.
7. Flashlight Fish
The Flashlight fish (Photoblepharon palpebratus) is a nocturnal fish of the Indo-Pacific. The species is well known for the photophores (light emitting organ) found under its eye, which harbours bioluminescent bacteria, allowing them to produce an eerie glow when seen in the dark. The fluorescent white to bluish-green glow is used to navigate, lure prey, communicate with one another and avoid predators.
8. Firefly Squid
The Firefly squid (Watasenia Scintillans) or the sparkling enope squid is found throughout the western Pacific Ocean. It gets its name from the flashing lights that resemble those of a firefly.
This spectacular glow-in-the-dark squid is equipped with special light-producing organs called photophores. Each tentacle has a photophore attached to it, which emits a deep blue light. The lights can be flashed in unison or alternated in an endless number of animated patterns. When flushed, the Firefly squid can even control these lights to scare off other predators, communicate with other members of its species, or lure in prey!
9. Clusterwink Snail
Terrestrial snails produce a glowing light from their foot to attract mates. But the Clusterwink snail (Hineas Brasiliana) is the first discovered to use the shell-flashing trick as a form of self-defense. This sea snail can flicker their spiral shells like dim, blue-green light bulbs. It emits bright blue-green flashes of light like an alarm when other creatures rub past its shell. The light is produced from the mantle tissue and shines through the pale translucent shell, which acts to diffuse the light so that the whole shell glows.
10. Sierra luminous millipedes
The eight species of millipedes in the genus Motyxia are the only millipedes that glow in the dark. Emission of a greenish-blue light is uniform across the exoskeleton, and all the appendages (legs, antennae) and body rings emit light. Luminescence is generated by means of molecules called photoproteins which generate light upon combination with oxygen or other oxidizing agents. These bugs use bioluminescence as a defence strategy to outwit predators, according to a new study.