The Top 10 Deadliest Animals in the World - Owlcation - Education
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The Top 10 Deadliest Animals in the World

Larry Slawson received his Master's degree from UNC Charlotte in 2018. He has a keen interest in biology.

From the deathstalker scorpion to the marbled cone snail, this article examines the world's deadliest (and most dangerous) animals.

From the deathstalker scorpion to the marbled cone snail, this article examines the world's deadliest (and most dangerous) animals.

The World's Deadliest Animals

Throughout the world, a number of poisonous and venomous animals exist that are capable of inflicting serious harm (or death) on the human population. From the deathstalker scorpion to the marbled cone snail, this work examines the 10 deadliest animals known to exist worldwide. It ranks each animal according to their potential for causing human fatalities in the absence of medical attention.

Selection Criteria

In order to rank the world’s deadliest animals, a number of basic criteria were necessary for the extents and purposes of this work. First and foremost, each of the animals discussed below are ranked according to the overall potency of their venom (or poison) in relation to humans and animals. Second, fatality rates based on exposure to each animal’s toxins are considered. Finally, and perhaps most importantly, the average amount of time between exposure (to each animal’s toxins) and death is considered, with the assumption that no medical treatment was taken by an individual following a bite, sting, or ingestion of the animal’s toxins. This final criteria is crucial for this work, as a variety of antidotes and antivenoms exist to counteract the toxic effects of most animal species.

While imperfect, the author believes that the selection criteria employed for this study offers the best means for ranking the world’s deadliest animals.

What is the Difference Between a Poisonous and Venomous Animal?

Before a discussion of the world’s deadliest animals can take place, it is important to first understand the difference that exists between “poisonous” and “venomous” species. Poisonous refers to an animal that releases its toxins through a non-aggressive means (i.e. from being consumed or touched). Venomous, in contrast, refers to a species that is capable of actively stinging, biting, and injecting its toxins into a victim’s bloodstream.

In both cases, venom and poison are classified as toxins. However, venom is only effective when it is allowed to enter the bloodstream of an individual (or animal), whereas poison is capable of being absorbed through the skin (or from ingestion). In short, the primary difference between the two substances lies in their molecular composition, as well as the method for which they are delivered.

The infamous deathstalker scorpion.

The infamous deathstalker scorpion.

10. Deathstalker Scorpion

  • Average Size: 3.5 to 4.5 inches (9 to 11.5 centimeters)
  • Geographical Range: North Africa, Central Asia, and the Middle East
  • Conservation Status: Unknown (Insufficient Data)

The deathstalker scorpion (also known as the “Palestine yellow scorpion” or “Omdurman scorpion”) is a species of highly-venomous scorpion from the Middle East. Found throughout the Sahara, Arabian Desert, Central Asia, and Arabian Peninsula, the deathstalker is widely considered one of the deadliest animals in the world due to its potent venom that is lethal in small doses to humans and animals alike.

Deathstalkers are relatively small scorpions with an overall length of 3.5 to 4.5 inches (9 to 11.5 centimeters). They are typically yellow in coloration, and possess thin tails, weak pincers, and slender pedipalps. Abdominal regions on this species are usually orangish-yellow, and are accentuated by gray stripes that extend from the head to the tail. As with most scorpions, the primary diet of the deathstalker is insects (such as earthworms and centipedes) as well as spiders. Within their natural habitat, the deathstalker is commonly found under stones, vegetation, and brush that provides them protection from the elements.

Deathstalker Scorpion Sting Symptoms

The deathstalker scorpion possesses a venom containing four highly-potent neurotoxins. This includes chlorotoxins, charybdotoxins, agitoxins, as well as scyllatoxins. Upon stinging their victim, the venom immediately begins to attack the neuromuscular and cardiovascular sectors of the body, causing extreme pain and swelling at the injection site. Within minutes, headaches followed by nausea, extreme vomiting, and abdominal cramps also begin, followed by diarrhea. As the venom progresses into the victim’s bloodstream, fluid retention in the lungs is common and is often accompanied by convulsions and difficulties with breathing. In its final stages, high blood pressure and complete respiratory failure begin and are followed by death if medical treatment is not sought quickly.

Treatment

Although antivenom exists to counteract the effects of the deathstalker’s sting, the scorpion’s venom is incredibly resistant to this form of treatment and often requires tremendous doses to be effective. Anaphylaxis and pancreatitis are also common reactions to the venom and should be monitored carefully. As a result, stings by a deathstalker are considered a medical emergency and require prompt treatment to avoid long-term complications or death. In addition to antivenom, treatment revolves primarily around palliative care to mitigate the severity of the sting’s symptoms (and pain). This is followed by intravenous fluids to maintain proper hydration and electrolyte balance.

In regard to fatality rates, deaths are usually uncommon for healthy adults. Nevertheless, those with pre-existing conditions (such as heart problems, respiratory distress, or a history of allergic reactions), along with children and the elderly are extremely vulnerable to the scorpion’s venom. In addition, survivors are known to exhibit long-term complications such as heart issues and muscle pain following stings. And while these issues occasionally resolve within months, some symptoms may become permanent.

The deadly pufferfish.

The deadly pufferfish.

9. Pufferfish

  • Average Size: Fluctuates (Depending on Species)
  • Geographical Range: World’s Tropical Regions
  • Conservation Status: Unknown (Insufficient Data)

The pufferfish (also known as the “blowfish”) is an extremely deadly species of fish from the Tetraodontidae family. Found in most of the world’s tropical regions, the pufferfish is closely related to the porcupinefish, and is considered one of the most poisonous vertebrates in the world. Considered small to medium in size (depending on the species), some of these fish are capable of growing upwards of 39 inches at maturity. They can be easily identified by their elongated bodies, distinct eyes, as well as their natural ability to “puff” or “expand” to several times its normal size.

Pufferfish Poisoning Symptoms

The pufferfish contains a deadly toxin within its body known as tetrodotoxin. It is considered by the medical community to be one of the most toxic compounds found in nature. Consumption or contact with the pufferfish’s poison is considered a medical emergency, as the fish’s poison rapidly attacks the victim’s body. Symptoms of pufferfish poisoning usually begin within 10 minutes, with numbness and tingling of the mouth being among the initial issues felt. This is followed by excess salivation, nausea, and extreme vomiting. As the poison progresses in the body, paralysis or loss of consciousness are common, followed by complete respiratory failure and death if medical treatment is not sought immediately.

Treatment

If consumed, one of the primary treatments for pufferfish poisoning is to induce vomiting, or to pump the stomach in order to empty its contents. In more recent years, consumption of activated charcoal has also proven quite effective in neutralizing the effects of the pufferfish’s poison, along with palliative care, life-support equipment (and measures), as well as intravenous fluids. In spite of these treatment options, however, no effective antidote has been developed to combat the effects of tetrodotoxin. Primary treatment revolves around keeping victims alive past the 24-hour mark. If this is achieved, symptoms usually begin to resolve on their own over the days that follow.

The Dubois' sea snake.

The Dubois' sea snake.

8. Dubois' Sea Snake

  • Average Size: 2.6 to 4.8 feet (0.80 to 1.48 meters)
  • Geographical Range: Coral Sea, Papua New Guinea, Arafura Sea, Timor Sea, and the Indian Ocean
  • Conservation Status: “Least Concern” (Population Stable)

The Dubois’ sea snake is a highly-venomous species from the Elapidae family of snakes that includes cobras and the inland taipan. Regularly classified as one of the deadliest species of snake on the planet, the Dubois’ sea snake is an exceptionally dangerous animal with the ability to kill a human with a single bite. They are commonly found throughout the coastal waters of Australia and the Indian Ocean, and can be easily identified by their long bodies, fin-like tail, and brown coloration that is accentuated by dark crossbands.

Within its natural habitat, the Dubois’ sea snake is commonly found along coral reefs and areas containing large quantities of seaweed (owlcation.com). From here, the snake is known to hunt a variety of fish and crustaceans, with parrotfish and surgeonfish being their most desirable form of prey.

Dubois’ Sea Snake Bite Symptoms

The Dubois’ sea snake possesses an extremely potent venom that is comprised of numerous myotoxins, nephrotoxins, cardiotoxins, as well as postsynaptic neurotoxins. Combined, each of these compounds deliver a devastating blow to their victim’s body, as they actively attack the heart, lungs, and central nervous system. Bite symptoms usually begin within minutes of an attack, and include headache, nausea, vomiting, abdominal pain, diarrhea, and vertigo. Once the powerful toxins seize control of the central nervous system, convulsions and paralysis are common, and are generally followed by kidney failure, cardiac arrest, or complete respiratory failure (leading to death).

Treatment

Bites from the Dubois’ sea snake are life-threatening emergencies, as untreated bites are considered fatal nearly 100-percent of the time. Seeking medical treatment, however, is often problematic due to the remote nature of the snake’s habitat. This, in turn, prevents individuals from finding help in a timely manner, resulting in death for the majority of snakebite cases.

Nevertheless, if hospitalization can be achieved by victims, standard treatment for a Dubois’ Sea Snake bite includes multiple rounds of CSL Sea Snake Antivenom, followed by intubation and ventilation, as well as dialysis to prevent damage to the kidneys (toxinology.com). Intravenous fluids and palliative care are also utilized in most treatment plans to maintain hydration and to keep pain at a minimum. In spite of this, long-term complications are common for survivors, with organ damage being one of the most commonly cited complaints. For these reasons, the Dubois’ sea snake is easily one of the most dangerous animals on the planet, and should be avoided at all costs.

The deadly marbled cone snail.

The deadly marbled cone snail.

7. Marbled Cone Snail

  • Average Size: 30 to 150 millimeters (1.1 to 5.9 inches)
  • Geographical Range: Indian Ocean and Western Pacific Ocean
  • Conservation Status: “Least Concern” (Population Stable)

The Conus marmoreus (commonly referred to as the “marbled cone snail”) is a species of predatory sea snail from the Conidae family. Endemic to the Indian Ocean and Western Pacific, the marbled cone snail is an extremely venomous species with the capacity to kill humans (and animals) with a single sting of its tail. The animal can be easily identified by its relatively large shell that reaches 30 to 150 millimeters, along with its spire-like shape, and distinct coloration that includes orange and white, or black with white dots.

Within their natural habitats, the marbled cone snail is commonly found along the ocean floor, near coral reefs, rocks, seaweed, or sand. From this location, the snail feeds primarily on other snails (including others in its own species). The animal accomplishes this feat by using a harpoon-like stinger to subdue its prey. This, in turn, results in paralysis allowing the marbled cone snail to devour its prey without resistance.

Symptoms of a Marbled Cone Snail Sting

The marbled cone snail possesses an extremely potent venom that contains a variety of conotoxins. These powerful peptides are known to produce a neuromuscular effect on their victims, resulting in fatality rates of approximately 75-percent (nih.gov). Most human-based stings occur when individuals attempt to handle the snail. Stings are considered extremely painful, with additional symptoms beginning within minutes of exposure to the toxin. This includes muscle weakness, excessive sweating, blurry vision, as well as paralysis of the extremities, reduced blood flow to the heart, and cyanosis (bluish discoloration of the skin). This is generally followed by necrosis of the wound-site, cardiovascular collapse, coma, or respiratory failure (leading to death).

Treatment

Stings from a marbled cone snail are life-threatening emergencies that require immediate treatment. To date, no specific antivenom has been manufactured to combat the snail’s deadly venom, as numerous variations within the Conus species have made it nearly impossible to create effective countermeasures (nih.gov). Nevertheless, standard treatment usually involves admittance to the Intensive Care Unit (ICU), followed by intubation and ventilation to ensure proper breathing. This is followed by pressure immobilization of the wound-site, along with hot-water therapy to lessen the extent of pain.

In spite of these treatment options, deaths from a marbled cone snail remain extremely high for individuals. For the lucky ones who survive envenomation, long-term complications are high, with muscle pain and necrosis persisting for months (or years) after recovery.

The stonefish.

The stonefish.

6. Stonefish

  • Average Size: 14 to 20 inches (Depending on Species)
  • Geographical Range: Indo-Pacific Region
  • Conservation Status: Unknown (Insufficient Data)

The stonefish is a species of highly-venomous fish from the Synanceiidae family. Endemic to the coastal waters of the Indo-Pacific region, the stonefish is widely regarded as the most venomous species of fish on Earth. Reaching upwards of 14 to 20 inches (depending on the species), these fish are extremely dangerous to humans, with the ability to kill an average-sized adult with a single sting. They can be easily identified by their encrusted bodies that appear similar to stones or coral (hence their name), as well as their spiny dorsal fins. The stonefish also takes on a variety of colors, including red, grey, or orangish-yellow.

Within its natural habitat, the stonefish hunts a variety of fish and shrimp. Using ambush-style tactics, this species is capable of subduing (and swallowing) its prey (whole) in an astounding 0.015 seconds. To date, they have few predators in the wild, with sharks and rays being their only real adversary.

Stonefish Sting Symptoms

The stonefish’s venom is stored within its dorsal fin spines, and contains a deadly substance known as verrucotoxin (or VTX). This powerful toxin is known to attack the cardiovascular, respiratory, and central nervous systems of its victims. Envenomation usually results from swimmers inadvertently stepping on a stonefish’s back. When disturbed in this manner, the fish then produces a venom yield that is proportional to the pressure applied by the swimmer on its body.

Following envenomation, symptoms usually begin within minutes, and include severe pain at the wound site, difficulty breathing, nausea, vomiting, as well as heart rhythm irregularities. Without treatment, fatalities are common as the Stonefish’s toxins subdue the heart, lungs, and nervous system resulting in convulsions, paralysis, coma, and eventually death.

Treatment

Stings from a stonefish are considered life-threatening and require immediate medical treatment. This includes the administration of stonefish-specific antivenom, along with the application of heat to the affected area. Hot water, in particular, has been found to be effective at neutralizing both pain and surface-level toxins in the puncture site. This is sometimes combined with vinegar solutions, which helps to sanitize the affected area while also providing a measure of pain relief. In more severe cases, intubation and ventilation may be necessary for patients to maintain proper breathing. Full recoveries are common (when treatment is sought immediately); however, long-term complications generally arise from stings including muscle weakness, and organ damage.

Fortunately, fatalities from stonefish stings have steadily declined in recent years due to the widespread availability of effective antivenoms. Nevertheless, this highly-venomous fish accounts for numerous stings each year, and should be avoided whenever possible.

The infamous Belcher's sea snake.

The infamous Belcher's sea snake.

5. Belcher's Sea Snake

  • Average Size: 1.5 to 3.3 feet (0.4 to 1 meter)
  • Geographical Range: Indian Ocean, Gulf of Thailand, and Northern Australia
  • Conservation Status: Unknown (Insufficient Data)

The Belcher’s sea snake is a species of highly-venomous snake from the Elapidae family. Endemic to the Indian Ocean and Gulf of Thailand, the animal is considered to be the world’s most venomous (and deadliest) sea snake due to its extremely potent venom. Reaching only 3.3 feet at maturity, the Belcher’s sea snake is a relatively small species that can be easily identified by its slender body, fin-like tail, and chrome-like coloration that is accentuated by dark crossbands.

Within its natural habitat, the Belcher’s sea snake is commonly found near coral reefs where small fish and eel (their primary source of food) are both abundant and plentiful. As an ambush hunter, the snake is well-equipped to subdue food due to its lightning-fast striking ability, and venom that is deadly in only small amounts (owlcation.com). These natural abilities are further augmented by the snake’s ability to hold its breath for nearly 8 hours underwater; thus, providing the animal with ample time to hunt from the shadows.

Belcher’s Sea Snake Bite Symptoms

The Belcher’s sea snake possesses a highly-potent venom that is comprised of both myotoxins and neurotoxins. A single bite is powerful enough to kill an adult human in less than 30-minutes, making this snake an extremely dangerous species that should be avoided whenever possible. Symptoms usually begin rapidly after envenomation, and include vertigo, headache, nausea, abdominal cramps, vomiting, and uncontrollable diarrhea. As the venom progresses (seizing control of the lungs and internal organs), convulsions are common, and are generally followed by complete paralysis, uncontrollable bleeding, and hysteria. In its final stages, kidney failure and respiratory failure are the two primary causes of death.

Treatment

As with many sea snakes, bites from this species are life-threatening emergencies that require immediate treatment for survival. In fact, it is estimated that 100-percent of untreated bites are fatal for victims. Unfortunately, prompt medical attention is often difficult to acquire, as the Belcher’s sea snake’s habitat is extremely remote (causing most individuals to die before they can be treated). If proper care can be achieved, however, standard treatment involves several rounds of CSL Sea Snake Antivenom, along with intravenous fluids, palliative care, and pain mitigation therapy (toxinology.com). Dialysis may also be utilized to protect the kidneys from failing.

For those lucky enough to survive an encounter with this species, long-term complications are common, with heart, lung, and kidney damage being some of the most common issues. For these reasons, the Belcher’s sea snake is easily one of the deadliest and most dangerous animals on Earth.

The deadly inland taipan (world's deadliest snake).

The deadly inland taipan (world's deadliest snake).

4. Inland Taipan

  • Average Size: 5.9 feet (1.8 meters)
  • Geographical Range: Queensland and Southern Australia
  • Conservation Status: “Least Concern” (Population Stable)

The inland taipan is a species of highly-venomous snake from the Elapidae family. Although considered an extremely shy and placid animal by experts, the snake is widely considered the most dangerous land-based snake in the entire world due to its extremely potent venom. Endemic to Southern Australia and Queensland, the taipan is a relatively large species with an overall length of approximately 5.9 feet (at maturity). They can be easily identified due to their rounded snout, chevron scales, and coloration that varies between olive and brownish-black (owlcation.com).

Within its natural habitat, the inland taipan is commonly found in areas that possess clay-like soil (due to the number of burrows and holes that are present within this environment). Operating from a concealed den, the inland taipan is an extremely aggressive hunter that feeds on a variety of rodents, birds, lizards, and smaller snakes when the occasion arises.

Inland Taipan Bite Symptoms

The inland taipan possesses an extremely potent venom that is comprised of hemotoxins, nephrotoxins, myotoxins, and neurotoxins. Combined, each of these substances are highly-lethal to animals and humans, as the toxins are known to systematically attack the central nervous system, muscular-skeletal system, as well as blood, heart, and lungs of their victims. Untreated bites are considered fatal 100-percent of the time, with death occurring in as little as 30 minutes. To put the snake’s venom in perspective, a single bite from an inland taipan is capable of killing over 100 adult humans (or the equivalent of nearly 250,000 mice).

Following envenomation, symptoms are known to begin rapidly and include migraine headaches, convulsions, and complete paralysis within minutes. This is followed by coagulation of the blood, leading to poor circulation, dizziness, nausea, and vomiting. In its final stages, the toxins seize control of the body’s internal organs, leading to kidney failure, cardiac arrest, or complete respiratory failure (owlcation.com)

Treatment

Bites from this species are life-threatening emergencies that require immediate medical attention. Standard treatment involves the administration of taipan-specific antivenom, along with pressure immobilization of the wound-site. This is usually followed by intravenous fluids (for hydration purposes), as well as palliative care which aims to control pain (and make the patient as comfortable as possible). Although treatments are usually effective (when provided rapidly), fatality-rates remain high for both treated and untreated bites. Long-term complications are also common among survivors, with organ damage and muscle weakness being among the most cited complaints. For these reasons, the inland taipan is truly one of the most dangerous animals in the world.

The blue-ringed octopus in its natural habitat.

The blue-ringed octopus in its natural habitat.

3. Blue-Ringed Octopus

  • Average Size: 5 to 8 inches (12 to 20 centimeters)
  • Geographical Range: Indo-Pacific Region
  • Conservation Status: Unknown (Insufficient Data)

The blue-ringed octopus refers to a collection of four highly-venomous species of octopus from the Octopodidae family. Endemic to the Indo-Pacific region, the blue-ringed octopus is widely recognized as one of the most venomous (and dangerous) marine animals in the world. As their name implies, this species can be easily identified by their 50 to 60 iridescent blue rings, sharp beak, eight arms, and yellowish coloration.

Within the Indo-Pacific, the blue-ringed octopus can usually be found living in tide pools or shallow reefs found in the region’s coastal waters. From here, the animal is provided with a plentiful array of food, including crabs, shrimp, and occasionally smaller fish. After capturing its prey, the octopus uses its sharp beak to pierce the animal’s skin (or exoskeleton), before releasing its deadly venom. To date, this species is one of the most dangerous animals in the world, with the ability to kill an adult human (or animal) in only minutes.

Blue-Ringed Octopus Bite Symptoms

The blue-ringed octopus possesses a highly-potent venom that is comprised of dopamine, tryptamine, histamines, acetylcholine, and the deadly neurotoxin known as tetrodotoxin. This potent mixture of toxins is lethal in tiny amounts, making this species extremely dangerous to humans. In fact, it is estimated that one bite from the blue-ringed octopus is capable of killing 26 adults within just a few minutes of exposure. To make matters worse, many individuals don’t even realize they have been bitten due to the relatively painless nature of their bites.

Symptoms from a blue-ringed octopus bite often begin suddenly, and include nausea, abdominal pain, numbness in the throat and mouth, along with difficulty breathing, and chest tightening. This is generally followed by excessive bleeding, along with paralysis of the extremities. In its final stages, complete respiratory failure and cardiac arrest are common, resulting in death.

Treatment

Bites from a blue-ringed octopus require immediate treatment (within 10 minutes), as the toxins act quickly on the victim’s body, resulting in death shortly after. As a result, fatalities are common among bite victims. Standard treatment involves pressure immobilization of the wound-site, followed by intubation and ventilation to open the airways. And while no antivenom has been developed to combat the animal’s deadly venom, 4-Aminopyridine and Neostigmine have shown positive results in reversing the effect of tetrodotoxin.

For those who are lucky enough to survive an attack from the blue-ringed octopus, long-term complications are believed to be common, with heart and lung issues being among the most cited complaints from survivors. Fortunately, bites from this species are relatively rare due to the shy disposition of the octopus.

The poison dart frog.

The poison dart frog.

2. Poison Dart Frog

  • Average Size: 0.59 to 2.4 inches (1.5 to 6 centimeters)
  • Geographical Range: Central and South America
  • Conservation Status: “Threatened” (Population in Decline)

The poison dart frog (also known as the “poison frog”) is a species of highly-poisonous frog from the Dendrobatoidea family. Endemic to Central and South America, the poison dart frog is considered one of the most poisonous species on the planet. Average poison yield from this animal is capable of killing 20 humans within a matter of minutes. The animal gets its name from the fact that Native American tribes often use the frog’s poison when creating tips for their blowdarts. To date, nearly 170 different species of the frog have been discovered.

The poison dart frog is found primarily in the tropical rainforests of Central and South America. Within these areas, they are commonly found in areas close to fresh water, including lakes, swamps, and marshes. They can be easily identified by onlookers due to their small size (2.4 inches maximum), as well as their bright coloration that can be yellow, copper, red, green, blue, or black.

Symptoms of Poison Dart Frog Poisoning

The poison dart frog possesses a highly-potent poison within their skin known as batrachotoxin (which is classified as a neurotoxin by the scientific community). This powerful alkaloid is known to open the sodium channels of nerve cells, causing paralysis and death if it reaches an individual’s bloodstream (through either ingestion or from puncture sites in a person’s skin). Poisoning symptoms begin within minutes of exposure, and include muscle pain, weakness, nausea, and vomiting. This is generally followed by heart rhythm abnormalities, difficulty breathing, convulsions, hallucinations, and eventually paralysis. In its final stages, batrachotoxin poisoning can result in either respiratory collapse or cardiac arrest, leading to death (toxinology.com).

Treatment

As of 2020, no effective treatment or antidote has been developed to combat the effects of poison dart frog poisoning. Due to the potency of their poison, death can occur in as little as 10 minutes, leaving little time to seek medical attention in the majority of cases. To make matters worse, the frog’s poison is lethal at only 2 micrograms (the equivalent 2 grains of salt). For these reasons, the poison dart frog is a species that should be avoided at all costs.

Fortunately, poisoning is considered extremely rare as the animal is unable to inject individuals with its poisons on its own. As a result, poisoning generally occurs from unnecessary exposure to the frog’s skin. Simple avoidance, therefore, will go a long way in ensuring you aren’t poisoned by this deadly animal.

The box jellyfish (world's deadliest animal).

The box jellyfish (world's deadliest animal).

1. Box Jellyfish

  • Average Size: 10 feet (3 meters)
  • Geographical Range: Indo-Pacific Region, and the Tropical Waters of the Atlantic and Eastern Pacific Ocean
  • Conservation Status: Unknown (Insufficient Data)

The box jellyfish is a highly-venomous species from the Chirodropidae family. Endemic to the Indo-Pacific region, as well as the warmer waters of the Atlantic and Eastern Pacific, the box jellyfish is host to nearly 51 different species that are lethal to humans and animals. To date, it is considered the deadliest animal on the planet, with a single sting capable of killing an adult human in less than 2-minutes. As with most jellyfish, this species can be easily identified by their box-shaped bell (head), cluster of 15+ tentacles, as well as its pale blue coloration that is transparent.

The box jellyfish is found predominantly along warm coastal waters. Within this habitat, prey is both plentiful and abundant for the jellyfish, and includes plankton, crustaceans, fish eggs, as well as fish. Once an animal is snagged (and stung) within its large tentacles, the animal is able to consume its prey in less than a minute.

Symptoms of a Box Jellyfish Sting

The box jellyfish possesses an extremely lethal venom that is comprised of cardiotoxins, necrotoxins, hemolysins, as well as myotoxins (toxinology.com). Combined, each of these compounds deliver a massive attack against the body’s heart, lungs, and bloodstream (with deadly consequences). The primary source for the box jellyfish’s venom is its extensive tentacles which contain millions of cnidocytes. Upon contact with an individual’s skin, the jellyfish uses these devices to release millions of microscopic “darts” that excrete its potent venom into their victim’s bloodstream through a series of “stings.”

Symptoms of a box jellyfish sting appear immediately, and include excruciating pain at the wound site, followed by throbbing sensations in the affected area, hypertension, nausea, breathing difficulties, and heart rhythm abnormalities. In cases of severe envenomation, respiratory failure and cardiac arrest generally follow a sting within 2 to 5 minutes, resulting in death from either suffocation or heart failure, respectively.

Treatment

Stings from a box jellyfish are considered life-threatening emergencies that require immediate treatment. Unfortunately, fatalities are common due to swimmers coming into contact with the jellyfish in the water. As a result, many individuals die before they even make it back to the shoreline (in severe cases). In milder cases, additional time is afforded for the individual to seek help, allowing first responders the opportunity to suppress the venom before it spreads further into the body. Standard treatment for these patients includes pressure immobilization of the wound site, followed by extensive rinsing of the sting with vinegar. If administered rapidly, vinegar has been shown to be highly-effective at neutralizing venom while simultaneously deactivating cnidocytes along the skin (toxinology.com). Once in the hospital, "Box Jellyfish Antivenom" is usually administered to patients, followed by intravenous fluids, as well as intubation and ventilation.

In spite of advancements in treatment options, fatalities from the box jellyfish remain extremely high. It is currently estimated that nearly 20 to 40 people die from box jellyfish stings each year. And while survival is possible, this generally occurs in cases of mild envenomation only. With the capacity to kill upwards of 60 adult humans with a single sting, it is no wonder that the box jellyfish is the deadliest animal in the world.

Works Cited

Articles:

Images:

Wikimedia Commons

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2020 Larry Slawson

Comments

Pamela Oglesby from Sunny Florida on September 18, 2020:

First, I didn't know there was a difference between poisonous and venomous. It seems many of these animals live in the ocean The blue-ringed octopus is surely unuaual looking. I have heard of a dart frog before but I didn't know anything about it either. This is another interesting article about some of the dangers in this world, Larry.

Danny from India on September 18, 2020:

I know of Pufferfish but not aware of the others on the list. Heard they have to be cleaned thoroughly before eating.

I think this is a delicacy in Japan. The blue Octopus looks deadly.