91% of People Can't Name These Dangerous Sea Creatures. Can You?

By: Kennita Leon

This fish is small in size but quite a beautiful sight to see, with stripes of white, black, red and zebra colors on its body. Don’t be fooled by its beautiful colors though, as the lionfish has venomous fins that are not deadly but can cause immense pain and breathing difficulties to its victims as well as nausea in humans. These are found in the Caribbean and the Atlantic and they are part of the Scorpion family.

These dangerous predators have large, saw-like teeth that can kill an animal or human in one bite. The great white shark usually feeds on fish when they are young but eventually graduate to sea mammals, such as seals, as they get older. They aren’t even safe from their own kind, as many newborn sharks do not survive their first year because they are preyed on by other sharks, including their mothers. This shark is considered to be a threat to humans, as they have been known to attack us more frequently than any other shark.

Getting stung by a box jellyfish can cause blood pressure in humans to rise to dangerous levels. The victim can experience great pain and go into shock, which can be fatal. Unlike other jellyfish that feed while drifting through the water, the box jellyfish goes out determined to catch its prey. Though not all of the fifty species of jellyfish are fatal, this sea creature has caused the deaths of many people in Australia, as compared to other animals, like crocodiles and snakes.

Flower urchins or Toxopneustes, are often called toxic foot- in reference to the many venomous structures on its surface, that are tiny and toxic by nature and can be dangerous if stepped on. These are known as pedicellariae and they look much like the petals of a flower but contain venom that the flower urchin can launch at its prey even from short distances. This poison can cause scorching pain for hours as well as numbness and muscle paralysis throughout the body.

This is known as one of the most poisonous fish worldwide, no doubt due to its venomous spines that have been known to be fatal to humans. The stonefish usually releases the venom if it is stepped on, which is very easy to do due to its camouflaged appearance that can be mistaken for another sea object. These fish are fast-moving ambush predators that live close to rocks, waiting for their prey before swallowing it in seconds.

These animals are fierce predators, naturally armed with two sets of jaws and some even have blunt teeth to crack down on the hard shells of molluscs and crabs. Moray eels are also innovative predators, tying themselves into knots around the body of their prey, until they are able to munch on parts of their victim or swallow it whole. This method is similar to how snakes constrict their prey using their bodies.

Also known as the cloth of gold, this snail lives in a shiny yellowish brown and white shell in the Indo Pacific and the Indian Ocean. This deadly sea creature, which can also be found in Australia and other Eastern countries, is the most poisonous snail in the world. It injects a peptide called conotoxin into its prey through tiny needles in its teeth, which can have disastrous effects on its victims, particularly humans. The venom in this tiny snail is lethal to us and has the ability to kill up to 60 humans.

These large sea predators range from 10 to 14 feet in length and can weigh up to 1,900 pounds. These animals, which are identified by the tiger stripes along their bodies, are mainly carnivores. They have been known to consume just about anything they can get their razor-sharp teeth on. After the great white shark, they are considered to be one of the most lethal sharks worldwide, duly noted for their attacks on humans.

This cephalopod is a creature well known for its chameleon abilities, as it often changes its color or shape to avoid predators and also to capture its prey. This octopus is actually beige but has vivid blue rings on its body when it feels threatened in some way. The blue ringed octopus has a venom called tetrodotoxin, and has more than enough to kill 30 humans at once. It is one of the only species of octopus with such lethal powers.

This 1,000-pound estuarine crocodile can be found in many countries from northern Australia to southeast Asia. This nocturnal hunter has a frightening technique of drowning its prey then rolling it quickly in the water until its limbs are removed before feasting on it. The saltwater crocodile usually hunts birds and mammals and, scary enough, can live up to 65 years.

This tropical marine fish can be identified by its glaring teeth, elongated body, and fork-like tail. It can travel 25 miles per hour to catch prey such as snappers and anchovies, and also to evade predators like whales and sharks. The barracuda is attracted to shiny objects and so it frequently hunts golden or silver-scaled fish. It has also been reported that it attacks divers but the reason for this is unknown.

This is a flattened fish from the Elasmobranchs family of which sharks are also a part. They have acute senses and special pits on their faces to search through the depths of the ocean for their prey. These pits help them to pick up on the electric signals animals emanate when they travel through water. These animals, however, are named after their barbed tails that they use as self-defense to protect themselves from predators.

This seemingly harmless invertebrate looks much like a yellow petalled flower in the ocean. They use their pedal disk to glide through the ocean but also have a tendency to attach themselves to solid objects in the water. The tentacles of this carnivorous predator are used to capture their prey as the unsuspecting animal drifts by. These tentacles paralyze the prey with toxins before it is put in the sea anemone’s mouth. This silent killer feeds on mussels and crustaceans.

This dark predator has two sets of jaws and hinged teeth that are larger than its small body. As a result of its body’s development from tail to head, the dragonfish lacks two vertebrae but has increased flexibility that allows it to catch large prey. It can also produce its own light thanks to the Photophores that line its body. This frightening looking fish is armed with unique characteristics that make it one of the most dangerous predators.

This unique fish has a slender body and a mouth similar to a funnel, which it uses to literally suck the fluids and blood of other fish for food. It has distinct characteristics. Its funnel-shaped mouth is large and jawless with rounded rows of teeth and it has seven gills behind its eyes. This predator is considered to be a threat to nature’s ecosystem, due to its systematic habit of preying upon salmon, lake trout and sturgeon.

Needlefish are elongated marine animals that frequent the surface of warm, tropical waters. They are named after the straight sharp teeth they use to capture their prey in their long jaws. They feed on krill and other smaller fish in the ocean, but also pose a threat to humans due to their knack for leaping from the water. When doing so, they sometimes leap into fishing boats and have been known to injure and even kill humans with their sharp teeth.

This fish has many other names, including zebra surgeonfish, which refers to the blue-black and yellow stripes along its oval-shaped body. It is usually found in East Africa, the Indian Ocean and places like Japan and Hawaii. This fish has spines along its tail that usually lie flat against its body but point outwards quickly, as sharp as a surgeon’s blade when the animal is threatened- hence the name- ‘surgeonfish.’ These spines can cause deep lacerations on the victim’s body.

This sturdy, fierce looking sea predator is also known as the ugly toad or the oyster cracker, first due to its unpleasant appearance and then for its knack of cracking down on other oysters. It lurks the muddy depths of the ocean and lives along oyster reefs on the East coast of North America. It has an unusually large head and two sharp spines its uses for self-defense. The oyster toadfish is an omnivore but usually feeds on crabs and other animals with hard shells that it is capable of cracking with its large blunt teeth.

Pufferfish can be found in the fresh waters of the Amazon River and in the salt waters of the Red Sea. These slow swimmers are also known as balloon fish due to their ability to puff themselves up to three times their size when they feel threatened. They also have spines along their bodies that pop out like needles. They also carry tetrodotoxin, the same chemical the blue ringed octopus carries, which is 100 times more poisonous than cyanide.

It’s scary enough knowing that there are snakes roaming the land we live on but even more frightening knowing that there are sea snakes too! These 3-10 feet long predators love the warmth of the Pacific Ocean and the Indian Ocean where they feed on eels, fish and their eggs. The Beaded Sea Snake is the most poisonous type, with venom potent enough to kill about eight people with just a few drops. Luckily for us, they are unlikely to bite unless they feel threatened.

Nudibranchs are brightly colored mollusks that eat fish eggs, slugs, sponges, barnacles and other small sea animals. They are informally referred to as sea slugs.They have poor vision and develop their own toxins from food which they use for self-defense. Also, when they consume prey with nematocysts, they store it for later to arm themselves against predators.

This large-headed fish lives in temperate regions among coral reefs and is conveniently designed with feathery fins that enable it to camouflage itself among the reefs. The scorpion fish has a commanding presence and is a domineering predator. This omnivore lurks the temperate region of the Indian and South Pacific Oceans and hunts its prey of small fish and snails by stunning them with venom before devouring them whole.

This is the second largest seal species worldwide and is usually found underwater, in the cold climate of Antarctica. They have grooved teeth and strong jaws they use to prey on other marine animals like krill, fish, and other smaller seals. They have a particular technique for catching unwary penguins; as soon as they jump off the ice and into the water, the hungry seals capture the flightless birds.

Boxfish have a carapace shell of integrated plates that contribute to their box-like appearance. This hard exterior makes boxfish difficult prey but makes them dangerous predators. When hunting, boxfish emanate a deadly poison into the water that can kill smaller fish, worms, and mollusks on which it preys.

The fire coral is just yet another example of a beautiful but dangerous marine animal. They are relatives of sea anemones and jellyfish and grow in many different forms, such as into thin branches with large shapes or patches of color onto other corals. They have sharp exoskeletons that can injure one’s skin and a powerful sting released by their tentacles, that can cause pain and induce nausea and vomiting.

Sea cucumbers are echinoderms that can be found on the sea floor of oceans worldwide, particularly in the Asian region. They have a barrel-shaped body that resembles the cucumber plant on land and are usually found in colors such as brown, red or blue, depending on the species. When threatened, they discharge a toxic material known as holothurin along with their internal organs to defend themselves against their enemies. No worries though, as their organs are regenerated about a week later.

This type of jellyfish dwells in Australian waters and is one of the smallest and deadliest jellyfish worldwide. They each have four retractable tentacles and a body that is almost transparent, making it difficult to spot in the water. However, they are notorious for their sting with effects so powerful, victims develop a condition known as ‘Irukandjis syndrome’. The Irukandjis venom is not only in their tentacles but all along their bodies and can result in heart failure and death if medical attention is not administered promptly to humans.

The large grouper is an almost 800 pound and 8 foot-long fish that dwells mostly among the coral reefs of Australia, particularly in Queensland. This yellow and black fish is unique; it can live up to a remarkable fifty years and is also the largest fish in the world to live among coral reefs. It feeds on crabs and lobsters and is one of the shark's only predators.

This is a heavy, listless marine animal that is usually found in salt waters around the world. They are broad-headed carnivores with sharp teeth that feed on squid, crustaceans, mollusks and other small fish. Attempting to touch a toadfish is always a risk because they are known to bite and some carry venom in their spines. Toadfish are considered to be poisonous, due to the dangerous compound they contain (tetrodotoxin) which can be fatal to humans.

Also known as Orca, this whale is the largest member of the dolphin family and also one of the most popular, due to its friendly nature and ability to be found in many bodies of water worldwide. Killer whales usually weigh up to six tons and can be as long as 30 feet. They are apex predators so they are not hunted by any other animals in the food chain but instead feed on them, particularly sea lions and even sharks.

This armored looking fish has scutes along its sides, a long body and snout that it uses to navigate the muddy waters it frequently inhabits. Sturgeons date back over 200 million years and are sometimes referred to as ‘living fossil’ because their major characteristics have remained consistent throughout the years. This predator is similar to the shark in appearance, due to the presence of heterocercal fins along its tail.

This marine animal gets its name from its long jaw that looks much like that of an alligator. It is the largest of the gar species and can weigh almost 300 pounds and grow up to ten feet. Alligator gar are opportunistic predators that usually feed on fish or whichever animal is available, from turtles to dead animals. Though their flesh is edible, the eggs pose a threat to humans and are poisonous when digested.

Goblinfish have a distinctive but strange physical appearance; they are pink and have long blade-like snouts extending over their heads and underneath, a mouth shaped like a shark’s and sharp teeth to match. They are commonly known as goblin shark and have surprisingly fragile jaws and tiny receptors on their snouts. These help them to pick up the electrical energy of potential prey. Goblinfish use slow deliberate movements to edge closer to their prey before snagging them with their dozens of teeth.

This shallow water fish has rough skin due to the denticles that cover its small body. As a group, dogfish sharks are fierce predators that hunt together, navigating the waters and consuming any fish they snag between their powerful teeth. This small shark contains a mild poison that could be problematic for people with allergies.

If you have ever spotted this bizarre fish, chances are you may have run in the opposite direction. Stargazers have eyes that literally sit on top their huge heads and an equally large mouth with parted lips facing upward. They have short sharp teeth they sink into their prey, after hiding out in the sand waiting for crabs and other animals to come by. Next time you’re at the beach, careful not to step on this predator so that you won’t be afflicted by its large poisonous spines that give off powerful electric shocks.

The leatherback is the last member of the Dermochelyidae family of animals, which encompasses the seven turtle species. This endangered species is also one of the world’s largest reptiles, with an amazing mass of over 1,500 pounds and over six feet in length. All leatherbacks, both young and old, feed on jelly-like animals, such as zooplankton, that drift through the ocean. Unlike other turtles, they have smooth skin and flexible bones that enable them to dive deep into the ocean, where they migrate for extended periods, often consuming more than twice their body weight per day.

This marine animal gets its name from its 7-meter-long snout that acts as a razor sharp blade protruding above its lower body. Despite the fact that they share a similar appearance with sharks, they are actually large coastal dwelling sea rays that grow from 16-24 feet in length. The sawfish is relatively harmless, aside from its long snout armed with sharp denticles that it uses to defend itself. It is actually an endangered creature, with less than 10 percent of its species still alive.

The Triggerfish is a bright, tropical reef-dwelling fish that is the largest of its kind, growing up to 3.3 feet long. This beautiful fish is a ferocious predator that thrashes debris with its fins and blasts its way through the bottom of the ocean in search of worms and crabs. It is the enemy of most coral reef animals and other fish usually follow its lead to capture the remainder of its meal. They are notorious for their bad tempers and are known to issue painful bites to divers that can leave scarring.

The Giant king squid is a large deep ocean animal with big water-filled eyes and multiple parts: two tentacles, three hearts, and eight strong arms. These carnivorous invertebrates use their fins to move through water and their funnels to propel them forward. Giant squids are part of the deep sea animals that are known to grow much larger than other marine animals living higher up in the ocean. Squids can grow up to thirteen meters long and females can grow up to 10 feet longer than the males, making this animal one of the largest organisms.

This large predator dwells in nearly all of the world’s oceans except in frigid regions. However, not much is known about this fish, apart from the ability to easily identify it due to its flat slender frame and the adipose fin on its body. They are consumed by sharks and seals but are also armed with sharp teeth and large mouths that they use to feed on small fish and squid.

Also known as the devil ray, these are wider than other rays and can grow almost 25 feet in breadth. Their unflattering alias is derived from the cephalic lobes attached to their mouths that have a striking similarity to horns. These help them to bring animals such as plankton and small fish into their mouths. Atlantic mantas have distinct behaviors and features; they somersault into the air for unknown reasons and have 300 rows of teeth in their lower jaw that are covered in skin but are not used for feeding.

Piranhas are fish that live in coastal rivers and have become notorious due to their predatory nature and voracious appetites. Though some are vegetarian and consume plant matter, the other species are known for their relentless bite and razor sharp teeth that they sink into prey, after attacking them first in the eyes or tail. The red bellied piranha is considered to be the most aggressive type but legend suggests that all species will attack any living thing that threatens their young or if they are really hungry.

It is commonly known as the Goliath tigerfish due to its large size of up to 110 pounds and its razor-sharp tiger-like teeth. This omnivorous fish hunts in packs, traveling at high speeds and using its interlocking teeth to snag unsuspecting prey between its powerful jaws. They also have replacement teeth that are used in place of any that have been broken off. This predator is often considered to be as fierce as the South American piranha.

Dolphins are friendly mammals that have a range of over 40 species with the Bottlenose dolphin being the most popular. They do not chew their prey but instead swallow it whole and use their teeth only to snag it. Their bodies are well equipped for feeding, with one stomach for digestion and the other for storing food. They are also known as very intelligent and loving animals that look after their own kind, often caring for other sickly dolphins. Male dolphins, however, have been known to get very aggressive on occasion, sometimes even killing in their anger.

This brightly colored fish has broad oval features as well as arms and tentacles that they use to walk the ocean’s floor; the only species to use these for that purpose. These cephalopods are relatives of octopus and fish that usually camouflage their bodies to depict their mood to disguise themselves when hunting, and as a means of protection from predators. It is dangerous to consume this type of cuttlefish that has been found to contain a deadly substance as toxic as the one found in the blue ringed octopus.

Also known as the yellow-lipped sea krait, this animal is a long, yellow and black striped snake with a flat broad tail. It is a well-adapted animal that resides in the Indo-Pacific waters but visits land to reproduce. Its uniquely shaped tail allows it to move swiftly through the water and its body shape is similar to terrestrial snakes so it can easily adapt to conditions on land as well. It has other body modifications that enable it to adjust to different environments, such as its large lungs and valved nostrils. This sea krait is more venomous than rattlesnakes and cobras because its venom is ten times stronger.

This semi-translucent animal is also called floating terror and, though it is similar to a jellyfish in appearance, it is actually from a different class known as Siphonophorae- an army of organisms living together. Its venomous tendrils can extend up to 165 feet underwater and a dead man- of war can still give off an agonizing poison. They usually drift through water but can flatten their airbags and rise to the surface of the ocean but this is usually avoided due to lurking predators.

The Mosasaurus was the big bad of the ocean some 70 million years ago during the Maastrichtian age. They were theorized to have roamed the waters of modern Western Europe and North America.

This shark is known for sudden, sharp movements and the ability to contort its body. Unfortunately for them, their eyes are located on either side of their hammer-shaped snout, which can make it difficult for them to spot objects directly in their line of sight but also gives them 360 vision. The hammer helps to balance the shark’s body but it is also used to boot animals, such as octopus and other fish before it consumes them.

This colored jellyfish is round at the top with up to 1200 long tentacles extending from its body. These jellyfish may swim together as shoals and use their tentacles to sting, capture and draw their prey closer to them for consumption. They reside in the cold waters of the Arctic and northern Pacific region and they only live up to 12 months before they die.

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About This Quiz

If you found the movie “Jaws” fascinating and could still go in the water after seeing the film, you’ll love this quiz. From great white sharks to giant squids and rockfish, the underwater world is fascinating but dangerous! Whether it’s poisonous spines from a lionfish that you are trying to avoid or a paralyzing sting from a box jellyfish, there is a world of pain floating below the surface. Not put off yet? Great, then you may be the one out of 10 who can name these dangerous sea creatures. Take the quiz right now. 


The underwater world is a mesmerizing place with creatures that could’ve come straight from a sci-fi book or film. In fact, science continues to explore the mysteries of the deep, the dark and the silent corners of this wet world to uncover new aquatic life.

From sea caves to deep sea hydro-thermal vents, there are surprising creatures lurking in the depths. But you know which are the dangerous ones, right? From sea lampreys to dragon fish and killer whales, you probably can identify them all. Try your hand at it now, you may be more sea savvy than 91% of those who took this quiz. Click the button below and show us your smarts.

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