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5 Most Dangerous Fish in the World

Last Updated: 24.04.24


The world’s aquatic life is purely amazing. The waters of the Blue Planet are home to more than 30,000 species of fish, from the largest and most ferocious ones to the smallest and deadly.

Of course, while most of the species out there are harmless and would love a swim alongside you, there are some dangerous ones – even cute-looking – that will do only harm to you as soon as you approach them.

In order to ensure your safety and be more aware of your surroundings the next time you go for a swim, here are five of the most dangerous fish in the world.

Electric Eel

Probably one of the most popular species, as we get to see them quite often in movies and TV shows, the Electric Eel is a long and scaleless species of fish. They can grow up to nine feet long and weigh around 48.5 pounds.

The Electric Eel is a sluggish type of fish that can usually be found in slow-moving freshwater, searching for its prey, and can be seen from time to time emerging from the water to get some air. Because of the many blood vessels present in its mouth, this fish can use it for both swallowing its victims and for breathing, as a lung.

The region responsible for the electric discharge is the tail. The electric organs, so to say, can be found here and they derive from muscle tissues that are innervated by the fish’s spinal nerves. The Electric Eel can discharge between 300 and 650 volts, which is more than enough for you to feel shocked.

Having your hands on an Electric Eel is not recommended – if you want to hold it for a photo, you should get your most effective fishing gloves that have the required protection to handle such a fish, and keep it as far from you as you can, as they are known to struggle once they find themselves captured.


Tiger Fish

This fish can be usually found in Africa, in Lake Tanganyika and the Congo River. Fit for its name, the Tigerfish has razor-sharp teeth located on both of its jaws, making it a very efficient predator, hunter, and fighter – in case some other fish want to have a brawl and pick just the wrong guy, we mean fish.

The Tiger Fish is quite large on its own, but there is another species called the Goliath Tigerfish which is the largest of them all. It is said that one of these Goliaths can weigh up to 154 pounds. We said that it’s large on its own because one Tiger Fish would be enough to hunt down their prey. However, they hunt and attack in packs and mainly target large animals.

So, if you’ve spotted one of them, be sure that its friends are very close and waiting for the right moment to catch and devour their target.


Moray Eel

The Moray Eel is quite different from the ordinary eel most of you know – just because the Electric Eel is the one that’s displayed and shown around the most. This eel, while not being able to electrocute you, is equipped in a different way that can still hurt you a lot.

They have thick skin, which is also very smooth and scaleless. The mouth, where all of the action happens, is quite wide and has very strong, razor-sharp teeth. This means that the Moray Eel can hold onto its prey after biting it and it’s also able to do some damage if your leg is its target. They are known to be quite vicious when disturbed.

Wearing only fishing shorts in waters that are known to be inhabited by Moray Eels is clearly not a good idea – especially if you accidentally step near one of them. They are around five feet in length, but one species of Moray Eels, known as Thyrsoidea macrurus, can grow up to 11.5 feet long – so it’s not that hard to notice one when diving underwater.


This venomous fish is found in the tropical Indo-Pacific, mostly in its shallow waters. As you might have realized by its name, this species of fish live on the bottom of the water, among coral and rocks and in mud – so that it would be perfectly camouflaged.

The Stonefish has a large head and mouth, bumpy skin that’s covered by lumps resembling warts, and very small eyes. Just like a stone, these fish rarely move and do their best to blend in with the environment that surrounds them.

They are a threat to divers because they are very venomous. Because of the way they look, they can be easily stepped on – and when one does so, the Stonefish will inject venom through the grooves that can be found on its dorsal-fin spines.

Stepping on such a fish guarantees intense pain – and, in a worst-case scenario, even death. That’s why it’s better to rest your foot on plain sand than any rock you might see on the bottom of the shallow waters you might swim in.



The Pufferfish is one cute and tiny sea creature. However, what it can do – and also what can be done with it – is quite interesting.

Also known as a blowfish or swellfish – for obvious reasons – they come with the special ability to inflate themselves. This way, they go from their regular fish form to a globular form – but they still have more to show. Their skin is prickly, and when inflated these pricks stand out, ready to sting anyone that might accidentally touch the Pufferfish.

When it comes to teeth, they are fused and form a shape that resembles a beak. Most of the fish of this species are quite small, but there have been seen some that grew as long as three feet.

While the prickly bubble of a fish that is the Puffer doesn’t look so dangerous, the true danger lies inside. Their internal organs are poisonous, containing a venomous substance called tetrodotoxin. If ingested, it can cause death.

However, in Japan, where this species is called fugu, it is considered a delicacy – but it has to be prepared in a special way and only government certified chefs are allowed to cook such a fish. The chefs that want to cook fugu also have to pass several exams before being allowed to work in a restaurant – if the Puffer is not cooked properly, death caused by eating it is very likely to happen.


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