There are lots of creatures in the animal kingdom capable of producing their own light. Perhaps you are familiar with some of them; others may come as a surprise. Interested in learning more about these amazing animals? Read on to explore our top 10 list of animals that produce light.
What You'll Learn Today
1. Firefly
Fireflies are some of the most well-known creatures that produce light. They are found throughout the world in tropical and temperate climates, and there are more than 2,000 species of them.
Fireflies produce a blinking, greenish glow from their tails on summer nights. They do this primarily to attract mates, but the glow also serves to discourage predators from eating the fireflies.
Some firefly species have the ability to synchronize their blinking lights, causing spectacular light shows for short periods each summer. In other species, females have been shown to select mates based on the strength and intensity of their light.
2. Deep-Sea Anglerfish
Deep-sea anglerfish swim the temperate and tropical oceans of the world and are found widespread throughout the oceans’ pelagic zones. These scary-looking fish are known for their esca, the fleshy growth protruding from their heads that glows in the dark depths of the deep-sea waters.
Anglerfish use their glowing esca as a lure for prey. The glowing protrusion attracts other deep-sea animals, drawing them close to the fish, which then snap up the prey with their large mouths and sharp teeth.
The glow produced in the esca is actually caused by a bioluminescent bacteria that lives inside of the fish. In addition to attracting prey, it can also help female anglerfish attract males.
3. Jellyfish
There are more than 2,000 species of jellyfish found throughout the world, inhabiting oceans from surface to deep-sea levels. Though they are not all bioluminescent, it’s estimated that about half of all species have the ability to produce light.
Jellyfish typically use their glowing abilities to escape predators, as they may emit glowing particles to distract them while they escape or produce bright flashes to startle them. They may also glow when searching for food, as their glow enables them to disguise themselves as zooplankton while looking for their own food sources.
Some species of jellyfish, like the comb jelly, can use their movements to scatter the light they produce, creating beautiful rainbow effects. This can both attract prey and frighten away predators.
4. Krill
Krill are tiny crustaceans found throughout all of the world’s oceans. They are common prey for whales, squid, penguins, fish, and other marine animals, which often eat thousands of them at a time.
Krill have the ability to glow and produce bright lights; sometimes, they can even reflect this light away from themselves using a special lens. Oddly enough, scientists aren’t sure of the reasons behind their light production.
It has been suggested that the light-producing effects may be for communication between krill or may be motivated by some other schooling behavior. It may also be to attract mates, but scientists have not been able to observe evidence of this.
5. Squid
Squid are molluscs found in many oceans throughout the world. Some of them are bioluminescent, using their light to hide from predators in a phenomenon known as counter-illumination.
These incredible squid species can produce light that mimics sunlight coming from the ocean’s surface. This helps them to blend in with their surroundings, allowing them to camouflage using light rather than hiding in the shadows.
Some of the most well-known bioluminescent species are the firefly squid, the midwater squid, and the Hawaiian bobtail squid. These species have either bioluminescent bacteria or special organs in their bodies that allow them to light up.
6. Lanternfish
Lanternfish are abundant in the deep seas of the world’s oceans, with around 250 species found worldwide. As their name suggests, they are capable of producing light within their bodies, which they use for a variety of purposes.
Lanternfish use the green, blue, or yellow light patterns they produce to spot both prey and predators. They also use it to help them camouflage and to find mates.
Lanternfish have special organs within their bodies that help them produce light. The patterns and colors of light vary from species to species and may be different between the males and females of single species as well.
7. Click Beetle
There are many species of click beetles in the world, and not all of them are bioluminescent. The ones most notable for producing light are found in the Americas and belong to the Pyrophorus genus.
Adult click beetles have two glowing spots that look a bit like eyes on their backs. Their larvae and eggs also have the ability to glow in the dark.
Click beetles use their glowing spots to attract prey insects at night. The green glow is similar to that produced by fireflies, though the spots maintain a steady light rather than blinking.
8. Sea Snail
Sea snails are a large and diverse group of molluscs found in many of the world’s oceans. Some of these slow-moving creatures have the ability to put on an impressive, almost electric-looking light show.
It’s unclear exactly how sea snails use their bioluminescence. Some scientists think they glow to communicate with each other from the shell, while others believe they do it to ward off predators by diffusing the light and making themselves appear larger.
While not all sea snails produce light, those that do tend to be very bright. They may appear almost translucent with an electric blue glow.
9. Plankton
Plankton are single-cell organisms that have characteristics of both plants and animals. Found throughout the world’s oceans, they are unable to propel themselves and are thus at the mercy of the waves and currents that move them along.
Many types of plankton are bioluminescent. Zooplankton, which have more animal-like characteristics than the plant-like phytoplankton, typically produce light by squirting glowing substances into the water to confuse predators or attract mates.
The colorful, shifting light patterns produced by plankton can be incredibly beautiful. Check out the video below, which shows plankton glowing in the waters off the shores of Wales:
10. Tasmanian Devil
Tasmanian devils are carnivorous marsupials native to Australia. Though these animals don’t produce light of their own, they can glow in the dark under specific conditions.
Tasmanian devils are biofluorescent, meaning they can absorb UV light and reflect it as a blue-green glow. This biofluorescence is most notable around their faces, especially the ears, eyes, and teeth.
A similar biofluorescence has been observed in other mammals as well, including opossums, squirrels, and platypuses. It is unclear why Tasmanian devils glow; there is some thought that it may have to do with attracting a mate or allowing the animals to identify themselves in the dark.
Conclusion
A number of different animals have bioluminescent and biofluorescent abilities, allowing them to glow or produce light. These creatures include fireflies, squid, anglerfish, jellyfish, and Tasmanian devils.
