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The most dangerous marine animals in the world

Do you want to meet the most dangerous animals in the marine world? There are those that have fearsome jaws and there are those that can do a lot of damage or even kill with their powerful venom, even people and other larger animals. It is about sharks, fish, jellyfish, snakes and even crocodiles and snails. Surprising?

Of course, it is not easy to find one of these animals on the coasts that we usually frequent to enjoy a day at the beach, but if we decide to go into the sea or the ocean we must take extreme precautions. Be amazed by this list of names and spectacular photos of the 10 most dangerous marine animals in the world that we present to you in AgroCorrn.

You may also be interested in: What is the ugliest animal in the world

Sea wasp or box jellyfish

The most dangerous animal in the marine world is, without a doubt, the sea ​​wasp or box jellyfish , scientifically called, Chironex fleckeri . It is a jellyfish and although many people believe that they simply produce hives and burns that can be more or less painful, the truth is that this particular species is poisonous. It is one of the most poisonous animals in the world , because its venom is lethal with a small amount, and more specifically, it is the most poisonous animal in the world.

It lives in Australian waters and many people have died over time from its sting, because by injecting just under 1 and a half milligram of its venom, this jellyfish is able to kill an adult human in a short time, without even give yourself time to swim back to shore. Like many poisons in the animal kingdom, it attacks the nervous system, producing paralysis, immense pain and, finally, causing a collapse of the nervous and cardiovascular systems, stopping the heart .

This terrifying animal due to the effect of its contact, is one of the largest jellyfish, as its head can measure about 25 cm but also counting its tentacles it can measure 3 meters and weigh a couple of kg.

White shark

This is one of the largest marine animals that we can find and at the same time one of the most fearsome and dangerous. The Carcharodon carcharias or white shark lives in temperate oceanic waters and in some temperate seas and is the largest marine predator in the world, as it can weigh 2 tons (2,000 kg) and in its adult stage it measures between 4 and 6 meters in length. They have 3,000 teeth with which they tear prey to eat, but they also use them to catch prey and gobble it up in one go.

They feed on both fish and marine mammals but, although they give us so much respect and fear and are really impressive animals, they usually do not approach humans, they do not usually attack us and we are not their usual or preferred food. They attack us because they feel threatened by our presence or out of sheer curiosity, to know what we are, many of their attacks are not deadly although they can be.

Sea snake

The cobras and sea snakes , scientifically known as Hydrophiinae are poisonous snakes and, indeed, its venom is more potent than cobras ground . There are several species of these such as yellow or striped, but all have flat or rowing tails, an adaptation to aquatic life.

These sea snakes live in the Pacific Ocean and the Indian Ocean. Their basic food is fish, crustaceans and mollusks, so we are not in danger of being their prey, but we are in danger of being attacked if they feel cornered, invaded or scared, because they attack us only to defend themselves. Its bite causes intense muscle pain, drowsiness, respiratory paralysis, jaw spasms and blurred vision, as the neurotoxins attack the central nervous system causing death shortly after, either by the dose or by asphyxia.

Lion fish

If it is not the most dangerous fish on the planet , it is certainly among the top rankings of the most dangerous fish . The lionfish or Pterois volitans , is a clear example of why poisonous animals have bright and showy colors, since they are white with brown or reddish stripes that stand out a lot, especially when it gives them some light when they swim closer to the surface.

They have long spines from head to tail, along their entire back, and on all their fins and tail. At the base of these spikes it has poisonous glands that produce and expel the poison through these spines when they need it, basically when they are pressed when being stepped on, caught, bitten … This poison produces great pain and can produce death from paralysis and suffocation.

Stone fish

Another of the most dangerous animals in the sea and ocean is the stone fish. This animal, scientifically called Synanceia horrida , is one of the most poisonous and has neurotoxins and cytotoxins, which makes it a very dangerous being for others in its environment and for us if we step on it by mistaking it for a stone or rock, then its appearance is similar and it is camouflaged. Its venom is found in its tips or spines that cover all its skin, but the most poisonous are in the pelvic, anal and dorsal fin areas.

They live in the Pacific Ocean and the Indian Ocean and their main food is crustaceans and small and medium-sized fish. Among the symptoms of a collision with this dangerous fish, apart from feeling a more or less strong sting when leaning on a rock, symptoms such as inflammation of the area, headache, pain throughout the body, high blood pressure, arrhythmias, dizziness stand out. , nausea, vomiting, seizures, muscle paralysis and cardiorespiratory arrest.

Blue ringed octopus

Octopuses are one of the 10 most intelligent animals in the world and there are some that are also poisonous, such as blue-ringed octopuses or Hapalochlaena . These cephalopod mollusks are another clear example of a poisonous animal that has bright colors to warn us, because as we see in the image, its blue rings are very showy along with the yellow of the rest of its skin.

This animal is one of the most dangerous because its venom is one of the most deadly, in fact it is the only octopus that can kill a human with its venom when biting, causing muscular or motor and respiratory paralysis. Anything less than a milligram of its neurotoxin can already kill an adult human. They live in the Pacific and Indian oceans and are no taller than 20 cm.

Marine crocodile

This is a reptile that we are used to seeing on land, in rivers and lakes, but there is a species that lives in the ocean: the marine crocodile or Crocodylus porosus . This species of large reptile is also commonly called saltwater crocodile, sea crocodile, estuary crocodile, since they also inhabit them, or porous crocodile by its scientific name.

It lives from Southeast Asia to northern Australia and is the largest crocodile in the world and, therefore, the largest reptile on the planet. There is quite a difference in size between males and females, since they usually measure between 2 and 3.5 meters while they usually measure between 6 and 7 meters and weigh between 900 and 1,500 kg or 1 ton and a half, and they weigh average ton or 500 kg. Its mouth is provided with 66 teeth and exerts a pressure of 1,770 kg , thus this is one of the most dangerous animals in the marine world.

Bull shark

This is the second shark on this list of the most dangerous animals in the marine world . This fish of the shark family lives in shallow or shallow waters, so if we go out to the open sea or the ocean we can find it more easily than other sharks. It is one of the sharks that usually comes closest to the coasts , since there it can reach shallow sandy bottoms. It lives in tropical and temperate waters in the Mediterranean Sea and the Atlantic, Indian and eastern Pacific oceans.

It is robust, compact and the area of ​​the back is marked with its fin more pronounced, in addition to its body, its head is small and flat with a pointed snout and its eyes are quite small. The bull shark or Carcharias taurus is just over 3 meters long and has three rows of teeth on each jaw. The teeth of this dangerous species are narrow, long and have a smooth edge, this does not serve as much to tear as other sharks, but is a perfect way to hold the prey and swallow it whole.

Poisonous cone snail

It may be surprising or curious but yes, among the most dangerous marine animals on Earth we find a snail. The poisonous cone snail is a species scientifically called Conus ateralbus that has a venom that can be deadly for humans and it is for many marine animals. Its venom produces paralysis and in a very short time death, especially for animals that need to come to the surface to breathe.

In the front part they have a retractable horn, that is, they take out and store as needed, and that it is connected to the gland that produces their poison and they use it to inject it. Without a doubt, it is one of the most dangerous animals in the ocean .


Although it looks funny, especially when it swells, the Tetraodontidae or puffer fish is a really dangerous animal if we eat it . The person or animal that dares to eat it will be poisoned and die in a short time, although in Japan it is known as Fugu and is considered a delight for the palate, something ironic.

It has poisonous glands distributed throughout most of the body, such as the liver, genitalia, skin and various organs or viscera. Specifically, its toxin can kill up to 30 people . Therefore, it can only be prepared and cooked by licensed chefs.

To finish, we leave here a video about the 10 most dangerous animals in the world so you can know the ranking taking into account also those who live outside the oceans.

Maria Anderson

Hello, I am a blogger specialized in environmental, health and scientific dissemination issues in general. The best way to define myself as a blogger is by reading my texts, so I encourage you to do so. Above all, if you are interested in staying up to date and reflecting on these issues, both on a practical and informative level.

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