9 Deadliest Sea Animals You’ve Never Heard of

Blowfish or puffer fish in ocean

As serene and and as inviting as the ocean floors might seem, you have to bear in mind that this environment is also very dangerous, some of the world’s deadliest creatures can be found in the sea or bottom of our oceans. Surprisingly, not all of them are what you might expect in terms of size, some of the world’s deadliest sea animals could be as small as baseball interms of size, animal like tiger shark could be as long as 5m in length. Here’s a look at the deadliest sea creatures living in the water. This list is subjective but we’ve taken our time to conduct a research here to find out the creatures of the deep ocean floors that conjure the most compelling combination of both aggression, fear, real pain or even death in some cases to humans, these are some of the most dangerous animals, even as small as some of them might look.

Deadliest Sea Animals in the World

1. Sea Snake

Even when included with the land going species, the sea snake still remains the most venomous snake on the planet. The amount of venom a sea snake could inject is enough to make the king cobra look like a harmless earthworm, just a few milligram of it’s venom is strong enough to kill up to one thousand people! The sea snake also known as hydrophiinae or coral reef snakes are a sub family of venomous elapid snakes. Though they evolved from terrestrial ancestors, most are adapted to aquatic life and are unable to move on land. They are commonly found throughout waters off South East Asia and Northern Australia.

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BelcherSeaSnake - deadliest sea animals

2. Stone Fish

The stonefish really has to be one of the ugliest fish I have ever seen, it doesn’t attack you but you don’t just want to step on it, it is usually found in the shallow waters of the tropics and ranges throughout the pacific and Indian oceans, the red sea and the great barrier reef, it looks unattractive with a skin that looks like a rock. Basically its poison causes severe pain, can sometimes cause shock, paralysis, tissue death and death if not treated, it can also result to other complications if treatment is not offered quickly, its pain is so excruciating that the victim might find himself or herself begging for the affected limb to be amputated, it’s one of the deadliest sea animals you’ve probably never heard of.

stone_fish - deadliest sea animals

3. Salt Water Crocodile

The salt water crocodile is found in eastern coast of India, south East Asia stretching south to northern Australia and the eastern coast of Africa. The saltwater crocodile is a formidable and adaptable predator, capable of taking almost any animal that enters its territory. It is an ambush predator waiting for the best opportunity to strike. It’s teeth are not designed to rip flesh but rather to hold onto the prey item, which reduces the animal’s chance of escape. These properties allow the crocodile to catch and drag the animal into the water, and then the prey is swallowed wholly or torn into pieces. The saltwater crocodile is considered as the most dangerous species of crocodile to humans.

salt_water_crocodile - deadliest sea animals

4. Blue Ringed Octopus

With no more than 8 inches in length, the blue-ringed octopus is endowed with enough venom to kill a human-actually, they have enough venom to kill nearly 30 humans in just a matter of few minutes. They are recognized as some of the world’s most venomous marine creatures. Even though they are so small in size and relatively docile in nature, it’s venom is 10,000 more powerful than cyanide. Bile from blue-ringed octopus will result to paralysis and if medication is not administered right away will definitely result to death. It might also shock you to know that the bite itself is painless meaning that you may not even be aware that you’ve been injected until you start feeling the symptoms. Since the blue-ringed octopus only bite if provoked, keeping your distance is the best treatment of all, especially since there is no anti-venom at all for this deadly sea creature.

blue ringed

Blue Ring Octopus via Saspotato

5. Box Jelly Fish

The box jellyfish (also known as a sea wasp) is a very dangerous creature that inhabits the north east areas of Australia. The jellyfish has extreme 60mins present on it tentacles, which when in contact within a human, can stop cartio-respiratory function within three minutes. According to the U.S National foundation, 20 to 40 people die from stings by box jellyfish every year in Philippines alone. The box jellyfish has enough venom to kill 60 adult humans within the shortest possible time. Its venom attacks the heart, nervous system, and skin cells hence it is considered to be among the most deadly in the world. It is so overpoweringly painful that human victims have been known to go into shock and drown or die of heart failure before even reaching the shore.

Jellyfish - deadliest sea animals

6. Sea Lion

The sea lions are characterized by external ear flaps, long fore flippers, the ability to walk on all four and short, thick hair. They are trainable and are major attraction at zoos but have been known to bite people. Sea lions are usually playful; however they can be territorial and dangerous especially during matting season. In as much as they are trainable, they can attack humans as well. Some local scientists said that sea lion behavior is unpredictable and can become suddenly aggressive.

sea lio

7. Puffer Fish

Puffer fish contains a toxin that is deadly to humans. There is enough toxin in one puffer fish to kill 30 people and there is no known antidote. Ironically these fishes are considered a delicacy in Japan despite the fact that one bad cut means certain death. The puffer fish contains a poison that is deadly to humans. This deadly poison called tetrodotoxin (TTX) is contained in this fat bodied fish. This toxin is said to be more powerful than cyanide and is enough to kill 30 people at a go. It results to difficulty in breathing on a person before leading to death. It is one of those deadliest sea creatures you’ll always want to avoid at all costs

Blowfish or puffer fish in ocean - deadliest sea animals

Blowfish or puffer fish in ocean — Stock Photo © Beth Swanson via depositphotos

8. CatFish

Surprised? yes,they appear very innocent, looking very harmless and peace-loving with their little and cute whiskers. On the  other way round, they can be very dangerous especially when provoked. The catfish reacts when threatened, it does this by pulling from the back and side fins three of its barbed spines. It might also interest you to know that its venom can still be active even after death.


9. Stingray

As deadly as the stinray might be, it only attack in self defence maybe when accidentally stepped on. For it to attack, it needs to be directly opposite its victim to enable it flip its long tail from the back then strikes its victim in front. The mechanism involved is that the stingray strikes with its tail, the force with which the stings tail enters the victims body causes its protective sheat to tear, hence the venom flows out into the victims wound. But it does not end there, in as much as the venom is deadly, pulling its sting out of the victims body can be very rough, rough enough to cause death.