Are Octopuses Dangerous? (to Humans and Other Animals)

Diver photographing a large red octopus

Many people are curious: are octopuses dangerous? These marine animals with eight long arms and large heads are both interesting and intimidating. They captivate our attention, but are we safe when they’re around?

This article will delve into the realities of octopus behavior. We’ll examine their defensive strategies and aggressive encounters and look at some real-life stories regarding octopus attacks. 

Let’s explore the world of octopuses and discover the truth about their behavior and safety.

Are Octopuses Dangerous to Humans?

Diver encountering a pale octopus in the deep sea

Generally, octopuses are not dangerous to humans. They keep to themselves and only become aggressive if they feel threatened. There have been a few rare instances when octopuses have attacked people. These attacks don’t happen out of nowhere; they mostly occur if the octopus feels trapped or provoked.

If an octopus does lash out, it’s usually trying to get away from something it sees as a danger, not to hurt humans on purpose. They’re also more likely to swim away than to attack. 

While octopuses aren’t really a physical threat to humans, there’s an important exception to consider: their venom. 

Some species, like the Blue-ringed octopus, possess highly potent venom, which can be extremely dangerous to humans.

One bite of this octopus can deliver enough venom to cause serious medical emergencies, including paralysis and respiratory failure.

While incidents involving this species are uncommon, they can happen, especially if someone accidentally steps on the octopus or tries to handle it.

Pro Tip: If a venomous octopus bites you, do not use a tourniquet, as it can make things worse by trapping venom in one area and reducing blood flow. This could harm the tissue around the bite. Applying a pressure immobilization wrap is a better option.

Are Octopuses Dangerous to Other Animals?

Yes, octopuses can be a danger to other animals. Octopuses are great hunters who catch prey like crabs and fish with their arms and crack shells with their beaks. They also use their venom to harm and catch prey. 

In some rare cases, octopuses have even attacked larger animals. They also exhibit some fascinating behavior when defending their territory and hunting. 

Other than their usual predatory behavior, here are some odd instances of octopuses posing danger to other animals:

  • Defending Territory: In a surprising display of territorial defense, the Gloomy Octopus (Octopus tetricus) has been seen throwing objects to protect its area. This is unusual for sea animals and shows how octopuses can pose a danger to other animals in unique ways. 
  • Clash with a Sea Lion: A sea lion and an octopus were caught on video in a rare fight near Canada’s coast. This fascinating combat shows how octopuses can hold their own against bigger animals.
  • Leaping on a Crab: According to a National Geographic article, an octopus was spotted jumping out of the water to attack a crab. This shows how octopuses can use unusual tactics to get a hold of their prey.
  • Octopus Cannibalism: In a notable case documented in a 2019 study, an adult Common Octopus was seen aggressively pursuing and eventually capturing a younger octopus of the same species. This rare event of cannibalism underlines the fact that octopuses can sometimes be a danger even to other octopuses.
  • Throwing Debris to Other Octopuses: Octopuses have been seen throwing things at each other. This unusual behavior might be how they communicate or show aggression within their species. This also supports the idea that they can pose a danger to their own kind.

On a similar note, I recently discovered an interesting fact about octopuses — they sometimes punch fish, possibly out of spite. I first heard about this in a BBC podcast featuring neuroscientist Dr. Amy Courtney as a guest.

In the episode, she explained that octopuses are great at hunting in coral reefs, where they chase prey into small spaces to trap them. But they’re not as effective in open water, so they team up with other fish to hunt.

Sometimes, if the fish gets to the prey first, the octopus might punch it. Dr. Courtney thinks the octopus may be doing this out of spite, among other reasons. 

This unusual behavior of octopuses has even been studied and written about in scientific research. You can read more about this odd phenomenon in this article.

Meanwhile, here’s a video showing how octopuses punch fish:

Octopuses Punch Out of Spite, Study Finds

These real-life stories help us understand how dangerous octopuses can be to other animals. Their ability to effectively hunt prey and defend themselves is crucial to their survival.

Octopus Behavior and Defenses 

Scuba diver observing a brown octopus inside a giant shell

Octopuses are really interesting animals known for their smarts and ability to adjust to different situations. They can find their way around complicated places, figure out puzzles, and sometimes even seem to play or dream

Now, when we think about the dangers octopuses pose, it’s also important to look at how they protect themselves.

Here are some of the ways octopuses defend themselves:

  • Beak: Located at the center of their arms, an octopus’s beak is its only hard part. They use it to bite anything that tries to hurt them. It’s also how they consume their prey.
  • Venom: Some octopuses can produce venom. They use it to stop their prey from moving. Also, they can use their beaks to inject venom and paralyze or scare away predators if they’re in danger.
  • Camouflage: Octopuses are great at hiding. They can change their skin color and texture to match their surroundings. This helps them avoid being seen by predators and prey.
  • Ink: If an octopus feels threatened, it can shoot out a cloud of ink. This ink cloud hides the octopus and can confuse the predator’s sense of smell and taste, giving the octopus a chance to escape.

In short, octopuses are not just smart; they have specialized ways to protect themselves. Their bodies are equipped with multi-functional systems that enable them to be dangerous or evasive whenever necessary.

Do Octopuses Attack Humans?

Octopuses are generally not aggressive towards humans, and attacks are rare. When attacks do occur, they are usually in self-defense rather than out of aggression. 

Below are some notable instances of octopus attacks on humans:

  • Lance Karlson Encounter: In Western Australia, a former lifeguard named Lance Karlson experienced an octopus attack at Geographe Bay. The octopus was popularized in social media as “the world’s angriest octopus.”​
  • Dmitriy Rudas’s Experience: In 2014, Russian diver Dmitriy Rudas filmed a giant Pacific octopus wrapping its tentacles around a fellow diver’s arms and equipment​​. Fortunately, no one was injured in this incident.
  • Jamie Bisceglia Incident: Jamie Bisceglia, while participating in a salmon fishing competition, experienced a painful incident when a small octopus she was posing with for a photo bit her on the face, causing intense pain and profuse bleeding.

These are just some of the few notable instances of octopuses attacking humans. While it’s uncommon, octopuses can sometimes react unexpectedly, especially if they feel in danger. 

Giving them space in their natural environment is important to avoid these situations.

Fun Fact: Did you know that octopus wrestling was once a popular sport? In the 1960s, divers would go into shallow water, find big octopuses, and pull them up to the surface. 

There were even big events for this, like the World Octopus Wrestling Championships in Puget Sound, Washington, that lots of people would come to watch.

Has an Octopus Ever Killed a Human?

Small octopus clinging to a coral branch

Yes, there have been recorded instances of an octopus killing a human. The Blue-ringed octopus, in particular, is known for its venomous bite that can be fatal to humans. 

Estimates vary, but according to a 1996 book, at least eleven fatalities have been attributed to the venom of the Blue-ringed octopus​​. In terms of physical attacks, there are many alleged cases, but only a few are documented. 

Notable accounts include a near-drowning of a diver in Toulon by a large octopus, reportedly weighing about 60 kilograms with 8-meter-long legs. 

Another incident occurred during research in the Marquises Islands, where American traveler Frederick O’Brien reported that a local’s relative was killed by a large octopus.

Additionally, “River Monsters,” a documentary series, described an attack by a giant octopus on the North American Pacific coast.

In 1989, Philippine fishermen rescued people from a capsized boat with suspicions that a giant octopus or squid was responsible. This incident also led to the drowning of a 12-week-old infant. 

While rare and sometimes questionable, these incidents underscore that certain octopus species, due to their venom or aggressive behavior, can pose a real threat to humans.

Fun Fact: In 2006, a 4-year-old boy in Queensland, Australia, survived a bite from a Blue-ringed octopus. 

He required 17 hours of ventilated support in intensive care after experiencing symptoms like vomiting, inability to stand, and blurred vision, but made a full recovery with no long-term effects.

What Is the Most Dangerous Octopus?

Among the many kinds of octopuses, the title of the most dangerous often goes to the Blue-ringed octopus. This small, colorful species, found primarily in the Pacific and Indian Oceans, carries a highly potent toxin called tetrodotoxin. 

Despite being small, this species has a very dangerous venom that can be deadly to humans. This venom can lead to paralysis and breathing problems, and there’s no cure for it.

Fortunately, these octopuses are not naturally aggressive. They usually bite only if they are bothered or picked up. They only use their venom to defend themselves, so if people don’t disturb them, they are not a danger.

Are Octopuses Friendly to Humans?

Octopus resting on a coral reef in shallow water

Octopuses are not inherently friendly towards humans. As wild creatures, they typically exhibit caution or indifference when encountering people. 

Their intelligence and curiosity may lead to occasional interactions with divers, but this should not be mistaken for friendliness. 

More often, octopuses prefer to avoid human contact and are unlikely to approach people. 

All things considered, while fascinating, octopuses should not be considered friendly animals in the way we typically understand the term.

What Should You Do If You See an Octopus?

If you encounter an octopus, it’s important to maintain a respectful distance. Avoid touching or provoking the octopus, as they can bite if they feel threatened. 

Remember, octopuses are known for their intelligence and curiosity, so they might observe you as much as you observe them. 

The key is to stay calm, avoid sudden movements, and enjoy the experience of seeing this fascinating creature in its natural habitat.

So, what do you think about octopuses? Do you think they are dangerous or not? Share with us your thoughts or concerns about the dangers of these fascinating creatures by leaving a comment below!

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