Scientists have been wondering for years how anglerfish produce light, and there is still much to learn about their mysterious light-producing abilities. Read on to discover more about this fascinating creature.
Read on to learn the most important details about Anglerfish and their unique Bioluminescence. You’ll be amazed at what these fish can do! Here’s a look at their bioluminescence and why it makes them so unique!
What is an Anglerfish?

Anglerfish are deep sea fish that are known for their ability to create light. They do this by using a bioluminescent organ called an esca.
The esca is used to attract its prey and is found on the front of the anglerfish’s head. It typically takes the shape of a worm or small fish, which can be as long as half an inch in size.
The male is much smaller than the female, so they have little need for adaptations. The male, however, is a parasitic mate and attaches itself to a female’s body through sharp teeth. Over time, he becomes physically fused with her, losing his eyes and internal organs. Female anglerfish carry up to six males and can support up to six.
Despite their large size and mouth, anglerfish aren’t very active hunters. Their blobby bodies mean they can eat anything, even the smallest prey. Interestingly, this fish has no fins, and can swim up to 120 feet.
The fish can grow to be almost as big as a basketball. They are carnivorous and can weigh up to 110 pounds. Those who know a little bit about the biology of anglerfish will be intrigued by their curious appearance.
As their scientific name suggests, anglerfish are nocturnal fish. Their luminescent organs, located in their mouths, help them lure prey. Their large mouths contain a multitude of sharp fangs angled inward to catch prey.
Some species also have a muscular flap on the top of their heads to attract prey. They vary in color and size and can range from dark brown to gray to red.
How Anglerfish Produce Light
How do anglerfish produce light? The answer is simple, they have bioluminescent bacterial symbionts in their fleshy escas. Anglerfish use this light to attract prey and avoid predators.
Scientists are not sure how anglerfish acquire these glowing symbionts, but it is likely that they have some sort of relationship with them. If that is the case, scientists should find out how anglerfish acquire these glowing cells.
Anglerfish are a fascinating family of fish. They come in many different colors and sizes, but most are gray or brown. Some are as large as 40 inches, with mammoth mouths filled with countless fangs.
They live in the deep ocean and have evolved special body features that allow them to manipulate light and attract prey. This luminous lure is used by anglerfish to attract prey and mates.
This bioluminescent behavior occurs because of a chemical reaction between luciferin and oxygen in the water. Luciferin is a protein that binds to oxygen and produces light.
Luciferin is a key component of this process, but many organisms produce a catalyst called luciferase to speed up the bioluminescent reaction. Female anglerfish have bioluminescent bacteria in their flesh. Similarly, the ceratioid species have a luminescent organ inside their body.
Why is the Bioluminescence of Anglerfishes Unique?
Several fish species acquire luminous symbionts from the environment. Hawaiian bobtail squid, for example, goes through a complex selection process to acquire the bioluminescent bacterium Aliivibrio fischeri. In contrast, deep-sea Osadex worms acquire the bone-digesting Oceanospirillales bacterial endosymbionts.
While we’re talking about bioluminescent fish, anglerfish are actually nocturnal animals, which means they only use bioluminescence when they’re hunting for prey. They use bioluminescence to attract prey, mimicking moths. As such, they draw prey to their lure tips. Because prey animals cannot resist light, they often approach anglerfishes.
The bioluminescent properties of anglerfishes are a result of their complex morphology and highly visible lures. Scientists believe these fishes use their bioluminescence to attract prey and communicate with their kin.
Scientists are still working out exactly how bioluminescent anglerfishes use this ability. Until recently, it was thought that only female anglerfishes were bioluminescent. In fact, female anglerfishes rely on bioluminescent bacteria to produce light.
Although the study authors cannot pinpoint the exact mechanism responsible for this unique phenotype, these findings point to a shared symbiont among anglerfishes. Molecular evidence suggests that anglerfishes acquire their symbionts from the environment.
Their symbionts are acquired through horizontal transmission. The authors also point out that anglerfishes and ceratioids have a genetically similar symbiont – E. luxaltus.