Top 14 Deadliest Fish in the World with Photos (And They’re Not Pretty)


Photo of Alligator gar showing two rows of fang-like teeth

These are the world’s most dangerous fish. You might find a few surprises on this list.

Have you ever heard of the Goonchfish? If you ever plan on visiting the Kali river region in India, I suggest you keep reading. There might be more deadly fish in the world than you ever suspected.

14 The Piranha

Piranhas are among the most well-known fish in the world, often depicted as ferocious predators in movies and novels. In real life, however, they are only truly dangerous to humans when starving, in which case they will attack anything that moves. Read on to discover the special circumstances that could lead to an attack.

There are roughly 30 distinct species of piranha in South America.

The largest is the red-bellied piranha, which may reach lengths of up to 20 inches, while prehistoric ancestors were twice as large, according to fossil evidence.

Their teeth resemble serrated blades that are so sharp and strong that they can cut through metal and can easily slice through flesh and bone.

Surprisingly, plant matter accounts for a significant portion of their diet, making them truly categorized as having omnivorous diets.

They can be dangerous because they have one of the strongest biting forces, paired with the ability to take on larger prey than themselves especially when they are in a large school.

If the river or creek they live in dries up and they are trapped in tiny pools and starving to death, they will attack people or any large animals crossing the river.

The last recorded case of a human death as a result of piranha attack was in 2015.

13 The box jellyfish

Box jellies are among the most common of the dangerous species in the oceans.

If you ever have the misfortune of coming across one while swimming, your best option is to exit the water as quickly as possible!!

There are more than 51 different species of box jellies found in oceans worldwide, and they are all venomous, producing some of the most powerful venoms found in nature. Luckily, only a few species are considered deadly to humans.

The most dangerous ones with some of the world’s most lethal venoms are indigenous to the Indo-Pacific and distinguishable by their box-like shape. 

Chironex fleckeri is the deadliest species of highly venomous box jellyfish. It can be found in coastal seas from northern Australia and New Guinea to Malaysia, the Philippines, and Vietnam. It is also known as the Australian box jelly and the sea wasp.

There have been at least 64 reported deaths in Australia from 1884 to 2021, making it the deadliest jellyfish in the world.

C. fleckeri has tentacles up to 10 ft (3 m) long covered in millions of cnidocytes with tiny hair triggers. As soon as the trigger is touched, it will unleash microscopic darts containing a potent venom.

The venom is so deadly and fast acting that 3-5 feet of tentacle wrapped around a leg or arm would likely cause cardiac arrest resulting in death within five minutes.

Each animal carries enough venom to kill 60 adult humans.

You can see why they are so dreaded.

One of the tiniest jellyfish in the world is also one of the deadliest. Read my article Irukandji Jellyfish Facts and Adaptations (Can They Kill You? Are they spreading?)

12 Stingray

Stingrays have long, pointed tails that make them easily identifiable, but over 200 species are known to exist and can be found all over the world. The largest can grow up to 17 feet long in the Indo-Pacific.

Even though they aren’t usually dangerous, you should approach them with great caution.

They aren’t aggressive by nature and their main response to danger is to swim away.  They typically employ their stings only when hunting but they won’t hesitate to protect themselves if they feel cornered. The stinger on their tail usually gets whipped up when they are accidentally stomped on by humans or assaulted by predators.

Most stings happen when swimmers unintentionally step on stingrays. If you enter waters with stingrays present, try to slide your feet through the sand rather than taking regular steps.

The jab of the stinger is more than enough to be concerned about, but they also have venom that can cause significant pain, edema, muscular spasms and can impede the wound’s natural healing.

There’s also the possibility that the point of the stinger will break-off under the skin which could call for surgery.

Human attack is uncommon, but it can be fatal, as we know from what happened to Steve Irwin ‘The Crocodile Hunter.’ Irwin approached too close to a stingray and suffered severe trauma as the stinger pierced his chest wall and went into his heart.

This is the best-known fatal sting case and occurred in 2006. It was just the second stingray fatality to be reported in Australia since 1945.  

11 The Muskellunge

The muskellunge, also known as the jackpike, is a species of freshwater fish native to North America. 

Some members of the family can reach six feet long and weigh up to 70 pounds.

In their natural habitat, pikes are considered to be the top predators.

Muskellunge are ambush predators that wait for their prey to swim by. When they spot their target, they will attack in an instant and devour the creature whole.

They typically hunt fish, but have also been known to hunt rats, frogs and even ducks.

They have such huge stomachs that they can consume objects up to two-thirds their own size.

Many avid fishermen have been caught off guard by the razor-sharp teeth and powerful jaws, which can take off a finger or slice to the bone in one nasty bite.

10 The Candiru

The candiru is a small fish reputed to swim into human orifices and get stuck there. Some would consider this the nastiest fish in the Amazon Basin.  There are fish in the amazon with enormous size and razor-sharp fangs, but this fish is much smaller, up to 7 inches or so.

The candiru might be small but it has a rather large and scary reputation. But the truth is not as impressive as fiction.

Candirus parasitize the gills of larger Amazonian fish, particularly catfish, and feed on their blood.

It is almost transparent, with short sensory barbels and backward-pointing spines on the gill covers, as well as around the head.

Despite the numerous horrifying accounts of assaults on people, relatively few of these incidents have been documented, and several of the claimed characteristics of the fish have been debunked as fiction or superstition.

They are almost certainly not attracted to urine. If they did end up in a human orifice, they would probably regret it as much as the human.

9 Alligator Gar

The alligator gar is one of the biggest freshwater fish in North America and the largest species in the gar family. Based on the fossil record they originally appeared about 100,000,000 years ago, during the Early Cretaceous.

Alligator gar showing rows of fearsome teeth. Museum specimen via Wikimedia

These huge fish have terrifying armament at their disposal, with a double row of sharp fangs.

Because they have kept some anatomical traits from their ancient predecessors, such as a spiral valve gut that is also present in sharks’ digestive systems and the capacity to breathe both air and water, gars are frequently referred to as “primitive fishes” or “living fossils.”

Their likeness to the American alligator, notably their large snouts and long, pointed teeth, is the source of their common name. According to anecdotal information, an alligator gar can get as big as 10 feet (3 meters) long, torpedo-shaped and covered with tough, serrated scales.

They can be found in the southern United States’ lakes and rivers, occasionally going out into the ocean.

Being ambush predators they wait patiently before snatching their prey with huge sharp fangs that can impale prey on contact.

They can pose a serious hazard to humans because of their size and amazingly sharp fangs, even though they are unlikely to attack people.

Even in self-defence, they could inflict terrible harm If they ever sank their teeth into a naïve or unprepared fisherman.

8 Sawfish

This is a unique species of ray called a sawfish that can reach up to 25 feet long.

The sawfish is one of the great white shark’s relatives with the most peculiar appearance, so named because of the long, saw-like snout (rostrum), which accounts for 20–28% of its total length.

This “saw” has sharp, tooth-like spikes on either side, a rounded tip, and an even breadth throughout.

Rather than having the wing-like bodies typical of many rays, they have many smaller fins. Being a member of the ray family, they have cartilaginous skeletons rather than bone.

Sawfish can slice prey by spearing through shoals of fish or by swiping back and forth. It strikes its target with quick sideways cuts that either stun it or impale it between its teeth. The cuts can occasionally be so strong that they can split a fish in half. A fish can be knocked to the ocean floor with even less violent blows, and the sawfish uses its saw to pin it there.

To find crabs, shrimp, and other prey, it uses the saw to dig into the sandy ocean floor. Sawfish can identify the fish and crustaceans they eat by sensing the electrical currents that originate from them using tiny pores on the underside of the saw (ampulae of lorenzini).

Sawfish are found primarily in tropical coastal areas, but may also be seen in warmer rivers and lakes

The waters off northern Australia are home to the largest population, with a much smaller population in Florida.

Scientists estimate that the total population of sawfish has decreased by more than 90% from their initial level, making them one of the most vulnerable fish in the world today.

The meat, eggs, and fins are highly sought-after by fisherman in many places, as are the spiked rostra, which are easily tangled in nets and lines.

It is simple to understand why this intriguing animal is in such danger when you consider that sawfishes take around 10 years to attain sexual maturity and reproduce. Human development is encroaching on the shallow coastal waterways, estuaries, mangrove swamps, and rivers where they live.

Although the sawfish has a macabre and frightful aspect due to its unusual rostrum, these animals typically do not hunt or injure humans on purpose. Only one incident of a sawfish assaulting a man without being provoked is known to exist.

Typically, they’ll strive to avoid conflict, but when trapped, they can use their powerful saws as weapons capable of inflicting serious wounds. If they feel threatened, they may flail about in self-defence, and this can be deadly to people.

7 Electric Eel

Electric eels can generate a deadly electric current; however, their name is a little deceptive considering they are a type of knife fish.

They do resemble eels in many ways because of their long cylindrical bodies and how they slither eel-like from side to side to propel themselves through the water.

They can be found in areas of stagnant water and can grow up to seven feet long.

There are three known species in the Amazon basin, with two new species being identified in recent years.

All species have been found to produce two distinct electrical charges via the hunter’s organ and the sacha’s organ.

They can produce a weak current, which can detect the presence of prey followed by a much more potent shock, which is how they kill or incapacitate their target.

The good news is that one shock from an electric eel is not enough to kill a healthy adult. 

The bad news is that such a shock would be extremely painful and could immobilize a person.

This would be an unfortunate if you were standing waist deep in the middle of a stagnant pond somewhere in the amazon jungle! Imagine falling into the water in a semi-paralyzed state unable to move your arms. You can see that the consequences could be deadly.

It’s not that the electric eels are trying to attack and eat a person, they would be acting strictly in self-defence. The problem is that a person could easily drown.

Electric eels like to live in groups. If you were in a pond with a bunch of electric eels and received several shocks the situation could very easily become deadly.

I almost experience heart failure just thinking about it!

6 The Goonchfish

The goonchfish is a voracious predator that is ominously referred to by locals as the “giant devil catfish.”

Photo of two men holding a large goonchfish.
Goonchfish are known to attack and eat people.

This is a large species of catfish that inhabits rivers in South Asia and can reach 7 feet long and weigh up to 200 pounds.

Between 1998 and 2007, there were a string of deadly attacks on people that were allegedly carried out by a goonch weighing 200 lb (90 kilos) in three villages along the banks of the Kali River in India and Nepal. Referred to as the Kali River goonch attacks, the victims were seen being pulled underwater by witnesses. There were several missing persons cases in this one stretch of river.

Despite intensive searching along the banks and underwater the missing victims were never located, and soon rumours spread of a dangerous river predator.

It’s now believed that some goonches were able to grow to enormous sizes and became used to eating people because the river was frequently used for Hindu funeral rites. It’s possible that they were devouring the corpses that were offered to the water and when these rituals ended, they took to hunting living alternatives.

Goonches were well-known in that area but had never been known to have acquired such a taste for human flesh before. Whether these stories of the goonchfish prove to be true or not, I suggest avoiding a swim in the Kali river.

5. Bull Shark

Despite not being the largest sharks, the bull shark makes it onto our list of the most dangerous fish.

Bull sharks are widespread, occurring in warm coastal areas throughout the world. Unlike most other sharks they can survive in both freshwater and saltwater.

They’ve been observed in river systems as far inland as 700 miles or more from the closest ocean.

They generally reach lengths of up to 8 feet and weigh up to 290 pounds.

They have a stocky build and all of this muscle is dedicated to one thing: hunting!

They feed on rays, other sharks, and fish but have a seriously bullish attitude that means they have a very low tolerance for being provoked and won’t think twice about attacking.

Pound for pound they have the strongest bite of any fish. With razor-sharp teeth lining their mouths, bull sharks can tear through flesh with little effort.

Bull sharks are one of the three species responsible for the majority of shark attacks on humans. Because they can swim up rivers, they are more likely to encounter humans, and often in murky water.

4 Barracuda

The great barracuda is a large species of predatory fish that’s endemic to the Indian Pacific and Atlantic oceans where they’re often found in the warmer regions at depths of up to 330 feet.

Some barracuda reach up to five or six feet long and weigh as much as 100 pounds. Look for black spots on the lower side of its body to help identify this fearsome looking fish.

The barracuda is one of the most vicious marine predators in the world.

They have powerful jaws and incredibly sharp teeth. They can reach speeds of up to 27 miles per hour in short bursts that allows them to catch up with virtually any prey they want

They also show a remarkable ability to plan. Even if they’ve recently eaten, they will herd fish into a confined area so they’re ready to hunt when they become hungry.

Human attacks are uncommon, however on occasion they will mistake a person for a giant predator and pursue them to feed on any food remnants they leave behind.

They do sometimes bite and are more than powerful enough to rip chunks of flesh and cause deep lacerations.

If you’re ever diving and see barracuda close by, be very careful. Stay close to your buddies and don’t make any frenzied moves.

3 Stonefish

Stonefish are unsettling-looking creatures! Originally native to the Pacific and Indian Ocean, they are now found throughout Florida waters and the Caribbean.

Photo of stonefish blending into coral and sand
Stonefish are so well camouflaged that you could easily step on one before you ever saw it.

This is the most poisonous fish known to man, with needle-like spines filled with fatal toxins ready to be injected if they are disturbed.

They spending their lives hidden among the rocks and coral on the seafloor, patiently waiting for prey to swim by. They are commonly found on tidal flats, which makes them particularly dangerous to people wandering around at low tide.

Most human injuries usually occur as a result of stepping on one, and the fast acting venom can be fatal. Stonefish stings are quite common because it’s nearly impossible to see the fish before it’s too late.

At the very least, it would be extremely painful. Stonefish anti-venom is the second most frequently administered anti-venom in Australia.

Fortunately, it has been decades since the last known death from a stonefish sting, but that doesn’t mean you should be too complacent. All it would take would be a particularly high dose of venom and you could be the next.

Failure to treat a stonefish sting could lead to widespread organ failure within several hours, which is a particularly gruesome way to die.

2 Goliath Tigerfish

Found throughout Africa, freshwater areas are home to goliath fish especially the Lake Tanganyika region and the Congo River basin.

They can grow to be five feet long and 110 pounds.

They have a truly terrifying set of needle-sharp teeth that precisely fit into grooves.

Jeremy Wade with Goliath Tigerfish, filming his TV series River Monsters.

They are known as the “mabenga” by locals, which means the dangerous fish

These deadly fish feeds exclusively on other fish and can completely destroy the stocks of more desirable species.

While there are no known fatalities from this species, there are certainly plenty of people with the scars to remind them. It is because of this ferocity that the goliath tiger fish is so dangerous.

There’s a long, detailed history of them attacking humans with serious consequences; nearby communities believe that dark spirits inhabit the bodies of the fish to make it attack people.

Because of its aggression, the goliath tiger fish is one of the top freshwater game species in the world, and every serious angler has it on their bucket list.

Looking at those teeth, I would choose another game fish for MY list!

1. Great White Shark

Great white sharks are the top predators in the ocean, and they are rightly feared by any creature that crosses their path.

Photo of shark swimming towards camera
Great white shark. Photo by Wai Siew on Unsplash

Adults can grow to be 20 feet long and weigh more than 5,000 pounds, and they are thought to be able to live for 50 years or more.

They are found in almost all open water and coastal areas around the world where the water temperatures are between 54- and 75-degrees Fahrenheit (12 – 24 degrees C). The highest concentrations of Great Whites are found in the waters close to Australia, the United States, and South Africa.

Great whites are fast swimmers and can reach speeds of up to 56 km/hour (35 mph). They can swim to depths of 4000 feet, so there are very few places they won’t go when they’re on the hunt.

These sharks have one of the strongest bites in the animal kingdom and some of the fiercest teeth you’ll ever see. Each triangular-shaped tooth is like a knife blade with serrated edges and can reach over 6 inches in length.

A great white shark can have up to 3,000 teeth at once, arranged in five rows. The largest and most frequently used sets of teeth are lined up along the front of the jaw. The top jaw of great white sharks has a row of 23–28 teeth, while the lower jaw has 20–26 teeth.

The great white shark, like all sharks, can develop and use more than 20,000 teeth over its lifetime. They will never run out of teeth because whenever one is lost, another one spins forward to replace it from a coil-like tooth reservoir of backup teeth in the jaw.

They have very few natural predators, although some Killer Whales have become specialists in killing sharks, including Great Whites, to be able to feast on their large livers.

Great whites are ambush predators waiting to surprise their prey. One of their most successful hunting strategies is to zoom up from the depths below and hit the prey from below at top speed. This attack often catapults both the shark and the prey into the air. The gnashing jaws and teeth grab into the unsuspecting prey as the shark whips its head back and forth, ripping off junks of flesh.

Great whites typically leave people alone, but because they attack with such force, they can create great damage with one initial lunge and bite. They say swimmers and surfers can be mistaken for seals and other prey species, but I suspect great white sharks know exactly what they’re attacking.  After all, they can sense the electrical pulses emanating from your beating heart!

It is often said that great white sharks don’t particularly enjoy the way we humans’ taste and find us to be far too bony to be worth their while.

I have no idea where this notion came from. I just know I wouldn’t want to swim with a Great White shark in the hopes that I look too bony.

According to the International Shark Attack File, great white sharks were responsible for 314 unprovoked shark attacks from 1580–2015. Of these, 80 were fatal.


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George Sranko

George Sranko, B.Sc., MA (Hons), is a retired professional biologist, photographer, author and speaker. He has explored fascinating nature topics and epic destinations for over 40 years, beginning with his first job as a National Park naturalist. George is a popular destination and science lecturer on cruise ships throughout the world, with hundreds of presentations under his belt. He has visited over 90 countries and happily shares his personal experiences and insights in a dynamic and entertaining style.

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