Top 10 Most Dangerous Fish In the World

If you’re anything like me, you will be curious about what kinds of fish there are out in our oceans. Here at Oyster Diving we have taken dive holidays all over the world and seen thousands of different fish species of all colours, shapes and sizes. And they still fascinate us.

However, as wonderful as it can be to experience diving and swimming with marine life it is just as important to be aware of the potential dangers in the ocean.

A lot of people fear the ocean and we didn’t write this article to scare you but simply to educate you on what to avoid. Today, we have written you our list of Top 10 most dangerous fish in the world. Read on if you dare – some of these might give you nightmares! 

1. The Puffer Fish

Top 10 most dangerous fish - the Puffer Fish

The puffer, also called a swellfish or blowfish, inflates when disturbed or threatened. The puffer fish has a highly toxic substance called tetrodotoxin, that is located in its liver, ovaries, intestines and skin. The tetrodotoxin poison affects the brain of its victim and can cause weakness, paralysis and death. 

These fish are extremely tough physically, due to their spiky skin, and have they have tough survival instincts. They are ranked among some of the most poisonous fish found in our oceans.

Where to dive with pufferfish: pufferfish are found in tropical waters, making Indonesia is the best place to dive with pufferfish. 

2. The Red Lionfish

Top 10 most dangerous fish - the Red Lion Fish

The Red Lionfish are famous for their venomous fin spines, which are capable of producing painful, though rarely fatal, puncture wounds. The fishes have large pectoral fins and elongated dorsal fin spines, and each species bears a particular pattern of bold, zebra-like stripes.

When disturbed, the fish will spread their fins and, if aggravated further, they will attack with their dorsal spines.

The red lionfish is one of the most well-known species and is native to the South Pacific Reef ecosystem. It relies on camouflage and lightning-fast reflexes to capture its prey, mainly fish and shrimp. If a human were to be stung by a lionfish it would not be fatal however, it would be extremely painful and can cause nausea and breathing difficulties. 

Where to dive with lionfish: if you want to dive with lionfish, visit the Caribbean and enjoy the warm water temperatures and incredible views.  

3. The Great White Shark

Top 10 most dangerous fish - the Great White Shark

The Great White Shark hardly needs an introduction, because it is one of the most well-known and powerful predators in the world. In the event of an attack, the great white shark tends to inflict a single bite on its victim and then retreat. In instances where the bite has been very large, there may be serious tissue or organ damage that could result in the death of the victim. 

Where to dive with great white sharks: there are many places you can dive with great white sharks, the five top being: Neptune Islands, Australia, South Africa, Gansbaai, Isla Guadelupe, Mexico, Stewart Island, New Zealand, Tiger Beach, Bahamas. 

4. The Moray Eel

Top 10 most dangerous fish - the Moray Eel

One of the most dangerous fish in the sea, the Moray Eel is vicious when disturbed and will attack humans. The jaws of the moray eel are equipped with strong, sharp teeth, enabling them to seize hold of their prey and inflict serious wounds. There are more than 80 species of moray eels. They tend to live in tropical and subtropical areas where the water is shallow and they can hide among the rocks and in the reefs. 

Where to dive with moray eels: the best places to dive with moray eels are Egypt, Belize, and Mexico. 

5. The Tiger Fish

Top 10 most dangerous fish - Tigerfish

Tiger fish are famous for their razor-sharp teeth that can inflict serious injuries to unsuspecting swimmers. They are marked, depending on the species, with lengthwise stripes and dagger-like teeth that protrude when the mouth is closed. Best avoided!

Where to dive with tigerfish: tigerfish can be found in Africa, in the river system of Zambia, and in the Congo. 

6. Electric Eel

Top 10 most dangerous fish - electric eel

The electric eel is a long South American fish that produces a powerful electric shock to stun its prey. The electric eel can grow to a massive 2.75 meters and weigh 22kg. Generaly sluggish, it prefers slow-moving fresh water where it is able to surface every few minutes to gulp air. The charge that is emitted from an electric eel is around 330-650 volts – powerful enough to jolt a human!

Where to dive with electric eels: electric eels are a South American fresh water fish and can be found in the Amazon basin. 

7. The Box Jellyfish

Top 10 most dangerous fish - box jellyfish

The Box Jellyfish is one of the most dangerous fish in the ocean and is considered to be the most venomous marine animal. It’s poison can cause death within a few minutes, while the marks left by its sting remain for a lifetime. The Box Jellyfish uses it’s poison to attack the cardiac activity. When attacked, the victim will experience an extremely low heart rate, extremely painful stings, and probably death. 

Where to dive with box jellyfish: you can go diving with box jellyfish in the waters off Japan, Australia, and in the gulf of Mexico! 

8. The Candiru

Top 10 most dangerous fish - candiru

This scaleless fish is commonly found in the Amazon River. The Candiru fish feeds on blood. Yes, you read that right, it feeds on blood. This little fish can be found in the gill cavities of other fish, eating away at them. But believe it or not, that’s not the scary part. The Candiru has also been known to attack humans. It enters the body through the urethra, it’s short spines and gills causing inflammation, pain, hemorrhages and even death in the unfortunate victim. 

Where to dive with Candiru: we recommend not getting in water with Candiru. However, Candiru can be found in the Amazon Basin in the countries of Brazil, Bolivia, Ecuador, and Peru. 

9. The Stonefish

Top 10 most dangerous fish - stonefish

Stonefish are commonly found in the tropical waters of the Indo-Pacific where they live in shallow waters. The Stonefish is a sluggish, bottom-dwelling fish that is extremely difficult to see as it blends in with its surroundings almost completely. When stepped on, it will inject high quantities of venom into its victim. The wounds produced from stepping on a Stonefish are intensely painful and can be fatal. 

Where to dive with stonefish: you can dive with stonefish in the Pacific and Indian Oceans. 

10. Piranhas 

Top 10 most dangerous fish in the world - piranhas

Piranhas are some of the most famous fish in the world. Often featured in movies as the bad-guy’s demise, piranhas have a cutting reputation. famous for their razor-sharp teeth, piranhas can apply a bite force that averages 20-30 times its own body weight. As a result, they can crush even the largest of animals in just a few minutes. 

Where to dive with piranhas: the best place to go diving with piranhas is in Japan. 

Have you come across any of the world’s most dangerous fish? Let us know in the comments below, we would love to hear from you!  

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