The answer is depending on what you mean by deadliest.
there are many undiscovered species of fish in our ocean so it would be hard to say.
Here are some different fish that are known for being deadly:
barracuda- not an incredibly big fish, but very fast, one of the fastest in the ocean. they live in shoals and have very sharp teeth. they have attacked people before, and their attack is very sudden and quick.
shark- there are many different sharks in the ocean some harmless like the basking shark, others like the bull shark are more aggressive. white sharks are mostly thought to be the most dangerous but that is not necessarily fact. sharks bite through curiosity to see what an object is, and they are not particularly interested in humans although they will attack.
marlins- often known as sword fish, these are very fast, and have very striking colours, they do not attack humans but are deadly predators for their prey (fish).
There are thousands of others but these are just a couple, you can also get salt water crocodiles if that falls into your category.
The box jellyfish is considered one of the most dangerous sea animals in the world. Its venom can be deadly to humans and can cause cardiac arrest and respiratory failure. Other dangerous sea creatures include the saltwater crocodile, great white shark, and cone snail.
The piranha is one of the most vicious and dangerous fish in the world. Found in South America, these sharp-toothed carnivorous fish are known for their aggressive nature and powerful bite that can strip prey to the bone in a matter of minutes.
You must pick up the shark and smack the pygmy into the water and let him drown. A lot of answers say to get the sword fish but this is false
It isn't dangerous at all,On average, a sword-tail is about 2-3 centimetres long, and is completely harmless.Unlike it's usual name-mistakable Sword Fish, that can be up to 7 metres long with it's famous snout, that can be up to 4 metres long.
Flying fish are not typically dangerous to humans. They use their ability to glide above the water as a way to escape from predators. If startled, they may end up in boats or hit people, but they do not pose a direct threat to humans.
fish
In my opinion it isthe bull shark. There are many species of dangerous fish in all area's of the world.
jelly fishes
probably surströmming
The most dangerous fish in the world is the great white shark. it has very sharp teeth to grind its food. It its so much and never gets stuffed.
The box jellyfish is considered one of the most dangerous sea animals in the world. Its venom can be deadly to humans and can cause cardiac arrest and respiratory failure. Other dangerous sea creatures include the saltwater crocodile, great white shark, and cone snail.
The Great White Shark would be the more dangerous of the two.
Piranhas are freshwater and quite dangerous.
The most dangerous fish in the Bering Sea is the Pacific sleeper shark. These sharks are not known to attack humans, but they have powerful jaws and sharp teeth that can potentially cause serious injuries.
The piranha is one of the most vicious and dangerous fish in the world. Found in South America, these sharp-toothed carnivorous fish are known for their aggressive nature and powerful bite that can strip prey to the bone in a matter of minutes.
they are dangerous to the ecosytem
The blue-bottle jellyfish and the box jelly-fish. keep your distance.