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Dragonfish | A Magnificent Dragon-like Fish From The Deep |

Dragonfish are not huge and frightening creatures like their name suggests. Still, there are interesting facts about them that we think you should know.

Dragons are beautiful creatures that amaze us at any time due to their impressive body shape and their ability to breathe fire.

As interesting as they are, we can not see even one creature in this world because they are mythical creatures. But, some animals resemble the Dragon. One such species is the Dragonfish.

So, here we are with some fascinating facts about the well-known Dragonfish.

dragonfish

What is Dragonfish?

Scientifically named Stomiidae, Dragonfish is a family consisting of about 303 species in which the most popular are only a few species.

These fish live in marine life habitats, mainly in the deeper depths of the ocean, where they are well camouflaged against predators and prey.

Distributed around the Atlantic, Indian and Pacific oceans, they are found in large numbers near the coast of Japan and other countries.

They are named after the Dragon because of their Dragon like body shape and the large terrifying mouth. But, these fish can not breathe fire like the Dragon.

When it comes to the name “Dragonfish,” the same name is used to describe several other creatures like the violet goby, barbeled Dragonfish, and the Asian Arowana.

Some other fish families like Pegasidae and the Polypterus senegalus family are also named the Dragonfish. But, the Stormiidae family is the most known family with the name “Dragonfish.”

Dragonfish species

There are several popular dragon fish species in the Stomiidae family. The six main types of Dragonfish are Black Dragonfish, Malacosteus, Idiacanthus, Viperfish, Eustomias, and Aristostomias.

However, the name doesn’t limit to these species as there are over 300 species that distribute over 28 genera. However, most of these species are unknown and hidden under the deep sea.

In terms of other fish species named Dragonfish, there are multiple species of Dragonfish in both the Pegasidae family and the Polypterus senegalus family.

How Dragonfish looks like

Appearance-wise, most Dragonfish species share the same traits as the Dragon.

With an elongated slender body with a large head and mouth, Dragonfish can grow up to 2.5 feet in length. The appearance we have described below refers to the Dragonfishes of the Stomiidae family.

Color

Most species are dark in color, ranging from black to dark blue. Some may have green or silver stripes running down the length of their body, but they all have a dark shade.

The deep-sea Dragonfish is an exception to this rule as it has a red light-emitting photophore organ on the top of its head.

This light gives it a ghostly appearance in the dark waters. Overall, all dragonfish species have a camouflage appearance to match the deep-sea environment.

Head and mouth

Head of them are large and flat, with a protruding lower jaw. They have long, sharp teeth that can tear their prey into pieces.

The mouth is extensive and can open up to 180 degrees. This allows these fish to swallow their prey whole.

They also have extendable jaws that can extend up to twice their original length. The jaw can be quickly opened and closed to snap up prey.

Eyes

The eyes of them are tiny and cannot see clearly.

But, they have excellent night vision due to the presence of rod cells in their eyes. Another interesting fact about their eyes is that they glow in the dark.

Body shape

Bodies of them are elongated and slender with a long tails. They sometimes have small scales that give them a smooth appearance.

The body is covered in bioluminescent photophores that emit light. This makes them glow in the dark and helps them to camouflage into the deep-sea environment.

Size

Dragonfish in the Stormiidae family is relatively small that grows up to 26 cm. But the usual size is around 15cm. So, although these fish have a scary look, they are not that big in size.

Life span

There is no exact known lifespan of them since there are multiple species of Dragonfish. However, the most common ones, such as the Black Dragonfish, live up to 10 years in captivity if kept in proper conditions.

Male and female fish 

They show sexual dimorphism. The females are ten times smaller than the male specimens and have comparingly small eyes for their size.

The female specimens especially have a barbel that emits light which is absent in the male fish.

These barbels are attached to the chin of the female, and it has a light-producing photophore on the tip. It is speculated that this barbel might be used to attract mates or find food in the dark waters.

The abdomen of the female is larger than the males since they need to contain eggs. The male has a needle-like structure called a gonopodium used to transfer sperm to the female during reproduction.

Dragonfish behavior

They are predatory fish, and they mainly feed on other fish. They have a sharp predatory instinct and are known to attack their prey with great ferocity.

Some species like the viperfish can even swim at high speeds to catch their prey.

In terms of behavior, they are not very active during the day. They prefer to stay hidden in the ocean’s dark depths and only come out at night to hunt for food.

They are also known to be loners, and they do not associate with other fish species.

The only time when Dragonfish interact with other fish is during mating season. During this time, male will try to attract a female by flashing their luminescent photophores. If the female is impressed, she will allow the male to mate with her.

After mating, the female fish will lay eggs that the male fertilizes. The eggs are usually released into the water, where they will float and develop into larvae. The larvae will then hatch and grow into full-fledged Dragonfish.

dragonfish

How do theyproduce light?

They produce light with the help of photophores. Photophores are cells that contain light-producing chemicals.

When these chemicals (adrenaline) are activated, they produce light. The light produced by the photophores can be used for various purposes such as camouflage, communication, and attracting mates.

One of the most interesting facts about this fish is that it can produce red light.

Red light is the longest wavelength of light, and it is not visible to the human eye. However, Dragonfish can see red light, which helps them camouflage into the ocean’s dark depths.

Where Dragonfish live

They are found in the deep sea waters with little or no light. They are mostly seen near the hydrothermal vents and cold seeps.

Some species of Dragonfish can also be found in the mesopelagic zone, also known as the twilight zone. This is the zone where the water is dimly lit and the temperature is cool.

The water in the deep sea is usually very cold and has a low pH. It is also under high pressure.

They are specially adapted to these conditions, and they can live in waters that are as deep as 5,000 meters.

This fish is not found in all parts of the world. They are mainly found in the Atlantic and Pacific oceans. Some species of Dragonfish can also be found in the Mediterranean Sea.

The water temperature in the deep sea is usually quite cold, ranging from 2-4 degrees Celsius. The pH is also very low, usually around 5.5-6.5.

The depth of the water where Dragonfish live varies depending on the species. Some species can be found in waters as shallow as 200 meters, while others live in over 5,000 meters deep waters.

What do they eat, and how?

They are carnivores, and they eat mainly fish, shrimp, and other small sea creatures. They have sharp teeth that allow them to tear their prey into pieces easily.

Some dragonfish species also have a barbel (a fleshy filament) on their chin to taste their food before eating it.

They are known to attack their prey with great ferocity. Some dragonfish species like the viperfish can even swim at high speeds to catch their prey.

They are not very active during the day. These fish prefer to stay hidden in the ocean’s dark depths and only come out at night to hunt for food. They are also known to be loners, and they do not associate with other fish species.

Dragonfish breeding

They are egg-laying fish that release eggs into the open waters in which the male fertilizes them afterward.

There is little information about their mating ritual. However, we know that these fish use their photophore organs to communicate with one another. It is speculated that the act of spawning is also used as a way to socialize with other Dragonfish.

The larvae are known to be planktonic, which means they live in the open sea rather than on the seafloor. They eventually settle on the floor of the deep sea as they mature.

Importance

Ecosystem balance

Although these fish are small, they are apex predators in their habitat. As such, they play an essential role in maintaining the balance of the deep-sea ecosystem.

However, these fish are also threatened by some large apex predators, such as red founder fish, when they live in the upper parts of the water column.

Commercial importance

They are also commercially important. Some species are used in the aquarium trade, while others are caught for human consumption.

They are popular because of their dragon-like appearance and their ability to light up the dark waters of the deep sea.

As a food

They are an exotic delicacy around the world. Dragonfish are well known for their firm flesh and the nutty flavor of their oil.

They are often eaten whole, not including the bones, which are considered a delicacy in some parts of the world.

The most popular way to eat fish is to fry them. This cooking method brings out the fish’s natural flavors and makes them more tender.

Dragonfish can also be baked, boiled, or grilled. Dragonfish are a healthy source of protein and omega-3 fatty acids, making them a nutritious addition to any diet.

Although they are healthy and delicious, the sacks and spines of them are poisonous. Removing these parts before cooking or eating Dragonfish is crucial as these poisons are deadly.

Aquarium trade

They are a popular choice for aquarists because of its unique appearance and ability to produce light.

However, Dragonfish are not always easy to find in the aquarium trade. Some species are more common than others, but finding them in pet stores can be difficult.

Another reason why they are popular in the aquarium trade is that they are relatively easy to care for. Dragonfish do not require much attention, and they can live in a wide range of habitats.

However, there are several pieces of stuff to keep in mind when keeping Dragonfish in an aquarium.

They are a predatory species, so they should not be kept with smaller fish. They also need a diet that consists of live prey, so you should not feed them dried food.

Dragonfish Facts

In addition to the facts mentioned above, here are some further cool facts about Dragonfish that you might be interested in.

Most Dragonfish are scaleless

Scales are usual in most fish types, but most dragonfish species do not possess scales to protect their body.

Most Dragonfish have smooth skin, while few have hexagon-shaped scales on their body. About 180 known dragonfish species do not have scales in their body.

Dragonfish has protruded teeth

The Dragonfish has very sharp and long teeth that can measure up to 1.5 cm in length.

These protruding teeth are not only used to catch their prey but also to protect themselves from predators. The teeth are also used as a tool for mating rituals.

Dragonfish can produce their own light

The Dragonfish has the ability to produce its own light through a process called bioluminescence.

This light is used to attract prey and to communicate with other Dragonfish. The light is also used to camouflage the fish in the dark waters of the deep sea.

Dragonfish can vary in color

The Dragonfish can come in a wide variety of colors. This includes various shades of green, blue, purple, and red.

The color of the fish often depends on the depth at which it lives. For example, red Dragonfish are usually found in deeper waters than other species.

Dragonfish have Chlorophyll-filled eyes

They have chlorophyll filled in their eyes. Dragonfish are the only known creatures in the animal kingdom to have this.

Chlorophyll is the pigment that gives plants their green color, so it is likely that dragonfish use this pigment to help them see in the dark waters of the deep sea.

Dragonfish are found in all oceans

Dragonfish can be found in all the world’s oceans. They are most commonly found in the deep sea, but they can also be found in shallower waters.

They are a cosmopolitan species, which means they can be found in many different habitats worldwide.

The eyes of a dragonfish can produce red light

The eyes of a dragonfish can produce red light. This light is used to attract prey and to communicate with other Dragonfish. The light is also used to camouflage the fish in the dark waters of the deep sea.

Related Questions

What kind of fish is a Dragonfish?

The Dragonfish is a species of fish that is found in the Atlantic, Indian and Pacific oceans. They are most commonly found in the deep sea, but they can also be found in shallower waters.

They are a cosmopolitan species, which means they can be found in many different habitats worldwide.

Are Dragonfish rare?

Some dragonfish species are common in oceans worldwide, while some are rare. Even some dragonfish species like Idiacanthus are already extinct.

Since we are talking about a family consisting of more than 300 species, it is hard to say that they are rare.

Are Dragonfish poisonous?

Dragonfish are not poisonous. But their sacs and spines are toxic to humans. That is why all the chefs handling Dragonfish in the kitchen have to be very careful.

The venom of Dragonfish can cause severe pain and swelling. In some cases, this poison can even lead to death.

Can you eat Dragonfish?

Yes. You can eat Dragonfish. In fact, Dragonfish is a delicacy in some parts of the world. The flesh of the fish is white and tender. It has a light nutty flavor and can be prepared in a variety of ways.

How big do Dragonfish get?

Most Dragonfish species are small, with most of them measuring only about 5-6 inches in length. However, some dragonfish species like the Idiacanthus atlanticus the black Dragonfish, grow up to 16 inches in length.

Conclusion 

Dragonfish inhabit the deep ocean, which is well camouflaged against predators and prey.

Distributed around the Atlantic, Indian and Pacific oceans, Dragonfish are found in large numbers near the coast of Japan and other countries.

They are named after the Dragon because of their dragon-like body shape and the large protruding head and mouth with long teeth. They are fascinating creatures to observe.

Credit to : Indoona
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About Dr.Chamika

Hello, I'm Dr. Chamika. I am a Researcher in Water quality, Aquatic organisms, and Environmental chemistry. I am a passionate fish keeper, with10 years of experience. My mission is to help other aquarists experience the joy of fish keeping.