Top 10 Terrifyingly Deadly Sea Creatures

Top 10 Most Dangerous Sea Creatures

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The oceans of the world don't lack deadly and vicious beasts. Welcome to WatchMojo.com and today we’re counting down our picks for the top 10 Most Dangerous Sea Creatures. For this list, we're taking a look at the planet's most physically threatening sea-dwelling animals that specifically pose danger to humans. Creatures that don't target humans or that are mostly dangerous when consumed as food don't qualify – thus, we're excluding the puffer fish from this list.

Fast, vicious, and capable of incredible injury – that's a frightening combination. Growing as long as 7 feet, barracuda are also known for being quick swimmers... and for being keen on brutal ambushes. They lie in wait before charging forth and biting down on their prey, armed with teeth sharp enough to damage nerves and blood vessels. If that wasn't enough, a number of barracuda have ciguatera toxin in their flesh, which can leave victims with nausea, hallucinations and other side-effects.

Found most often in oceanic or brackish water, moray eels typically avoid contact with humans whenever possible. When sufficiently threatened, though, these creatures ensure their aggressors get what’s coming to them – and more. Moray eel bites can produce easily-infected wounds, on account of the eels having a large amount of bacteria in their mouths. And that's not getting into their ability to chase down and kill other fish with minimal effort – small sharks have even fallen victim to their attacks. Who ever said the electric eel was the only threatening eel around?

#8: Sea Snake

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And here we thought ordinary snakes had enough deadly surprises to offer the world. Alas, the sea snake – though typically nonchalant when it comes to other animals – still poses a danger thanks to its venom. On the rare chance that a sea snake, or coral reef snake, chooses to inject its toxin while biting a perceived attacker, a sizable list of symptoms are in store for the target. The after-effects range from elements of nausea to general aching and a tetanus-like ailment to even heart failure. It's a horrible fate, delivered from an otherwise passive animal.

Looks can be deceiving, that's for sure. This small breed of fish has an unusual look: it resembles a rock bed, which is very useful for warding off predators. Unfortunately, those who accidentally tread upon the stonefish will be greeted with sharp fins that can pierce through shoes. On top of the initial painful sting, victims also have to contend with a neurotoxin that can shut down their respiratory system and even cause their heart to fail. Yikes. Found in the Indo-Pacific area, the stonefish is a delicacy in some places – after cooking has destroyed the venom, that is.

It may seem passive, but don't dare underestimate it. The stingray, typically relaxed, can hold its own and even do serious damage with its sharp spear-esque tail. Stiffening whenever the ray detects a threat, the tail possesses a serrated tip capable of severing arteries and is lined with venom that particularly endangers mammals. The stingray's sheer deadliness was tragically shown when, in 2006, wildlife expert and television host Steve Irwin was killed by a stingray's tail repeatedly striking him in the heart.

The bull shark may be imposing, but the tiger shark is something else. This large shark has a reputation for attacking and eating anything – including smaller sharks – and is one of the sharks most frequently associated with fatal shark bites. Tiger sharks don’t seek out humans as food, but they do tend to linger in shallow waters and river mouths where contact with humans is most likely. What’s worse, their keen senses and calcified teeth allow them to make quick work of any prey they desire.

#4: Great White Shark

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The adjective “Great” being in this animal's name is less a statement of positivity and more a grim tribute to its ferocity. The Great White Shark's most immediately recognizable quality is its size; they can grow to over 25 feet in length and weigh over 7000 pounds. However, these sharks have another notable habit: they strike at their prey from below with their mouths wide open, allowing their razor-sharp teeth to do as much damage as possible. It's no wonder that about a fifth of attacks by Great White Sharks are reportedly fatal, given the viciousness on display.

Such a pleasant name for such a debilitating beast. In regards to killing power, the blue-ringed octopus’ claim to fame is its infusion of the neurotoxin TTX, or tetrodotoxin, into its bites. Humans in particular face the risk of TTX shutting down their respiratory system, which can mean death for those without immediate medical attention. Considering that one blue-ringed octopus contains enough TTX to kill up to 26 humans – within minutes - and that TTX is thousands of times more potent than cyanide, the threat here is potent.

Fear the crocodile, for it strikes when you least expect it. As the name suggests, the saltwater crocodile can very easily traverse open waters, allowing them to spread across Southeast Asia with terrifying ease. Saltwater crocodiles are reported to have a bite power 10 times greater than that of the Great White Shark – at the very least, its large size and weight make it frighteningly easy to trap its prey. During a battle in World War II, hundreds of Japanese soldiers crossing through swampland in Myanmar were reportedly killed by saltwater crocodiles. Stuff like this gives us pause... Before we unveil our top pick, here are a few honorable mentions: Keeltail Needlefish Cone Snail Portuguese Man o’ War

#1: Box Jellyfish

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When it comes to the dangers of the sea, size matters not. Hence, we have the box jellyfish, a class of jellyfish that compensates for its small stature with a largely unparalleled sting. Those subjected to the venomous touch of the box jellyfish's tentacles are said to undergo extreme pain and a burning feeling. Box jellyfish venom is reportedly so potent that some people experience fatal cardiac arrest within minutes of being stung. The worst part is how hard it is to detect a box jellyfish before it can cause harm, due to its almost-transparent appearance. Do you agree with our list? What sea creatures do you feel are the deadliest? For more sea-faring Top 10s published daily, be sure to subscribe to WatchMojo.com.