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.

Most Dangerous Fish in the World

Puffer Fish The puffer fish is a rather small fish that swims quite slowly, to the extent of even being clumsy. So why is it on this list? Look at its name again to get a clue. 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. This species 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. In addition to this, 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!

Piranha 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". 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. 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 If the long serpentine appearance of the electric eel doesn't shock you, the powerful voltage that it generates certainly will! 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.

Stonefish When ocean-dipping Down Under, be sure that you keep a close watch on what's exactly down under, lest you unwittingly step on a stonefish! This fish is named so, because it literally resembles a crusty stone, thus camouflaging perfectly in its environment. One false step on this fish and your dreamy weekend at the beach will turn into a nightmare! 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 Though at 12 inches in length the red lionfish may seem much less terrifying to be around than its namesake - the lion, believe us, it is just as deadly, if not more! Don't be fooled by its small 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. The red lionfish 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 a lot of pain and swelling. In large doses, this venom can lead to a 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 first sign of danger is probably those ominous looking horns on the head of the Atlantic manta, which will remind you of the horns of the devil himself! They are the manta's cephalic fins. Its enlarged wing-like pectoral fins, and the small, thin, and whip-like tail at its rear, should be enough to ring warning bells. Still, if you aren't struck by fear at the sight of it, be warned, because most members of the manta species possess one or more stinging spines on their tails, which are sure to bring down a lot of hell on you! Manta rays are related to sharks and skates. They thrive in the warm water habitats near continents and islands, and feed on the 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 Now this is a fish that does justice to its name, in its entirety! Known to grow easily up to six and a half feet, and weigh around 65 pounds, it is certainly a giant among the other inhabitants of the Congo river. Add to that its yellowish-blue eyes and a mouth full of 2-inch-long razor-sharp teeth, and you know why it is called a tiger! 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. This is why it has been honored with the title of the greatest freshwater game fish in the world.

The Great White 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. But what is it exactly that makes the great white so dangerous? Perhaps, it's the fact that it is the largest predatory fish in the world. On an average, 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. Further, they 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. 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.

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. Seems harmless? Look closely, and you will notice that 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). It 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.