Tap to Read ➤

10 Most Dangerous Fish in the World

Satyajeet Vispute
If you thought that with fish, you only needed to worry about which ones taste best for dinner, think again! We list a few of the most dangerous fish in the world, some of which might just have you for dinner!

Did You Know?

Along with deadly fish, the seas are also home to poisonous sea snakes, whose venom is typically much more toxic than that of land snakes.
What lies beneath the surface of the oceans, lakes, and rivers? Enchanting, water-filled, alien worlds, wherein there exists a variety of stunning and exotic creatures. They are so beautiful sometimes, that you might find yourself charmed into wanting to be there. But do not be fooled by their deceptive appearances.
Many water bodies around the world hide deadly secrets within their depths! There, lurking in places where you would least expect, are seemingly harmless, wonderful-looking creatures, which are in fact deadlier than any that you might encounter up here on the surface.
If you are intrigued, come and take a dive with us into the depths of the water-world, and examine some of the most dangerous fish found on our planet.

Most Dangerous Fish in the World

Puffer Fish

The puffer fish, or blowfish as it is called, has the ability to inflate itself to several times its original size when threatened.
It uses its highly elastic stomach and the ability to quickly ingest huge amounts of water and air to inflate itself into a large ball, making it virtually impossible for many aquatic predators to consume it. The puffer fish is a rather small fish that swims quite slowly, to the extent of even being clumsy.
The Puffer Fish possibly developed this ability to compensate for its slow swimming motion. Some puffer species also possess spines on their skin, making them all the more unappetizing.
Also, almost all puffers possess tetrodotoxin, which makes them foul-tasting and even lethal to their enemies. Tetrodotoxin is almost 1,200 times more potent as compared to cyanide, in humans, and one puffer contains enough of it to kill 30 adults. There is no antidote for it either. This makes the puffer one of the most poisonous fish in the world.
So, the next time you decide to go bully a small fish in the ocean, and it starts to grow into a ball, it is best advised that you do not wait around!


This species inhabits several major river basins in South America.
Most members grow to no more than 2 feet in length, and vary in colors from silver with an orange underbelly to a dark black. They have deep bodies, saw edge-shaped bellies, large blunt heads, and strong jaws which open up to reveal sharp triangular teeth that meet in a scissor bite.
In 1913, former president Theodore Roosevelt took a much publicized trip down the Brazilian Amazon. The locals intending to impress the president caught a bunch of Piranha and starved them. When Roosevelt arrived, they threw a live cow into the water, which the piranha devoured within minutes, leaving behind just its skeleton in a pool of red.
So stunned was the president by this display of ferociousness that he described the piranha as, "The head with its short muzzle, staring malignant eyes, and gaping, cruelly armed jaws, is the embodiment of evil ferocity; and the actions of the fish exactly match its looks".
Though piranha are attracted to blood, their ravenous violent reputation is somewhat exaggerated. These fish are omnivorous, and mostly feed on plants and scavenge on carcasses. It is true however, that they also resort to cannibalism when food gets scarce, and have injured and scarred many local fishermen that have gotten too close to them.

Electric Eel

The body of the electric eel comprises special electric organs with close to 6,000 specialized cells known as electrocytes.
Each of these cells acts as a tiny battery that stores electric charge. When it is threatened or is attacking its prey, the electric eel discharges all of these cells simultaneously, generating a short burst of electricity of nearly 600 volts, which is close to 5 times the power received at a standard domestic wall socket in the U.S.
Despite their name and appearance, Electric Eels are closer to carp and catfish, than to eels. They have long tubular bodies and flattened heads. They are typically dark-green or gray on top, and yellow on the underside. They can reach lengths of up to 9 feet, and weigh nearly 45 pounds.
They inhabit the murky stream sand ponds of Amazon and other regions of South America. They have poor eyesight, and have to rely on the low voltage (10V) that they generate, which acts as a radar to navigate and locate prey.
Human deaths, as a result of being shocked by electric eels, are very rare, though being shocked multiple times can cause respiratory or heart seizure, which may lead to drowning.


The Fish is named so, because it literally resembles a crusty stone, thus camouflaging perfectly in its environment.
The stonefish is one of the most venomous fish in the world. It sports a row of spines on its back, which it extends on being threatened or stepped on. Once these spines pierce into its enemy, venom is injected involuntarily through each spine.
The quantity of venom that is injected depends on the pressure applied on the fish - more the pressure more the venom.
Being stung by a stonefish is extremely painful. But that's the least of your worries! Its venom typically leads to rapid swelling, muscle weakness, temporary paralysis, extensive tissue damage, and in rare cases, may even be fatal. The stonefish is commonly found in the coastal regions of the Indo-Pacific and in Northern Australia.

Red Lionfish

The Red Lionfish is 12 inches in length, small in size and attractive red, brown, and white pattern of stripes.
Before the stonefish was discovered, the lionfish held the title of the most venomous fish. This fish possesses spines on its dorsal, anal, and pelvic region, which it uses to puncture its victim's tissue and inject deadly venom. A sting from this fish can cause lot of pain and swelling. Large doses of venom can cause cardiovascular collapse.
Lionfish are local to the Indo-Pacific, however, in recent years, many members of this species have invaded the Atlantic coast of the US. Experts believe that this invasion has been the result of aquarium releases and damage to the aquariums caused by Hurricane Andrew in 1992, when a number of captive lionfish might have escaped.

Atlantic Manta

The ominous looking horns on the head of the Atlantic manta, they are the manta's cephalic fins. Its enlarged wing-like pectoral fins, and the small, thin, and whip-like tail at its rear.
Most members of the manta species possess one or more stinging spines on their tails. Manta rays are related to sharks and skates. They live in warm water habitats near continents and islands, and feed on small fish and plankton that sweep into their mouths channeled by cephalic fins.
The Atlantic manta is the largest member of the family of manta rays. Known to grow to over seven meters wide, it is also called the giant devil ray. It is typically brown or black in color, and owing to its large size is very strong.

Goliath Tigerfish

It grows up to six and a half feet, and weigh around 65 pounds and is a giant among the other inhabitants of the Congo river. It has yellowish-blue eyes and 2-inch-long razor-sharp teeth.
The Goliath Tigerfish has a powerful long-range vision and excellent hearing, which allows it to easily locate its prey. It can also accelerate to lightening fast speeds of nearly 62 mph and so it has been honored with the title of the greatest freshwater game fish in the world.

The Great White

It is the largest predatory fish in the world. The great white can reach lengths of 4.6 meters, with some even reported to having exceeded 6 meters. They are also known to weigh up to 5,000 pounds.
They are found in cool coastal waters throughout the world. They typically have slate-gray upper bodies, and a white underbelly (hence the name). Their bodies are perfectly streamlined, and they have powerful tails which help them achieve speeds in excess of 15 mph when snooping in on their prey.
Those who have been around a Great White Shark, describe it as the perfect killing machine. Movies such as Jaws (1975) portray it as the ultimate monster.
Last but not the least, great whites have rows of close to 300 serrated teeth, nearly 3 inches long, which come together in a scissor-like bite. They use these to tear up the flesh of their prey, which includes lions, seals, small-toothed whales, and even sea turtles.
Though human beings are typically not in the great white's menu, over the years, there have been numerous reported attacks on people. It has been estimated that, of the more than hundred shark attacks that take place annually, one-third to half are those by great whites.
Recent statistics and research however, shows that most of these attacks are non-fatal, and are usually carried out by great whites, who out of curiosity bite into and then release their human victim. Thus, though it is still dangerous, the great white isn't the mindless ferocious creature that it is mostly portrayed as.
The White Shark have an extremely accurate sense of smell, which helps them locate their prey, along with other organs which are capable of detecting the minute electromagnetic fields generated by animals in the water.
They are known to be able to detect even tiny amounts of blood from a distance of up to 3 miles.

Box Jellyfish

Found primarily along the coast of northern Australia and the Indo-Pacific, the box jellyfish appears like an upside-down plastic bag floating in the ocean waters. It is usually pale-blue or transparent in color, and possess a box-shaped bell with around 15 tentacles hanging from it.
Each of its tentacles has around 5,000 stinging cells, capable of injecting a powerful venom, which can instantly stun/kill its prey (fish and shrimp).
The box jellyfish has developed such a potent venom so as to prevent its victims from struggling and damaging its delicate tentacles. The venom of the box jelly fish comprises toxins that attack the heart, nervous system, as well as skin cells. It is one of the deadliest known to humankind.
Being stung by a box jelly is excruciatingly painful, and may cause a human to go into a state of shock, and drown. It can even result in instant heart failure. Sting survivors experience pain for several weeks, and are often left with severe scars where the tentacles made contact with the skin.
Box jellys can reach up to 3 meters in length, and are one of the most developed members of its species. They are capable of swimming rather than just floating in the water like other jellyfish, and also have very well-developed eyes, albeit they still lack a central nervous system.


Some of the deadliest things in nature often come in small packages. This fact is supported by the candiru (Vandellia cirrhosa): an eel-like translucent fish, that grows no longer than 1 to 2.5 inches on an average. This tiny creature is also known as vampire fish, due to the fact that its feeds on blood, and is mostly found within the gills of other fish.
The candiru is a scaleless, parasitic catfish, that belongs to the family Trichomycteridae. It thrives in the waters of South America, typically in the Amazon river, and is known to attack animals as well as humans who bathe in these waters.
Typically, it enters the urethra, and extends the short spines on its gill covers to anchor itself inside its prey, and draw blood. This can lead to inflammation, hemorrhage, and even the death of the victim.