While most people think sharks are the deadliest creatures in the ocean, there’s something far more dangerous lurking beneath the water. The box jellyfish is considered to be the most venomous creature in the ocean. Just because they don’t have jaws filled with razor-sharp teeth, doesn’t mean these seemingly squishy creatures are any less dangerous than your menacing hammerhead.

The ocean’s most venomous creature

The box jellyfish, or Cubozoa if you’re going by its scientific name, has the most powerful venom in the ocean. If you’re stung by one of its ten-foot-long tentacles, your heart could stop before you even make it back to shore. This is how the box jellyfish got dubbed as the most venomous creature in the world. According to the U.S. National Science Foundation, there are around 50 species of box jellyfish. Box jellyfish are so venomous, they may be responsible for more deaths than sharks, sea snakes, and stingrays. If you were bitten by a black widow spider you’d actually have a better chance of surviving.

Box jellyfish quick facts

Box jellyfish mostly live in their own jellyfish neighborhoods in the waters near Northern Australia and the Indo-Pacific Ocean. You can also find a handful of box jellyfish species near Hawaii, the Gulf Coast, and the East Coast. There are only a few species known to live in all three of those regions, however. The box jellyfish has 50 described species.

These quick-killers have around 5,000 stinging cells on up to 15 tentacles. Each stinging cell has a tiny capsule of venom on it. These capsules fire their microscopic stingers at a rate of 37 miles per hour. Once a toxin is released, the box jellyfish’s prey is hit with a rapid increase in blood pressure. This spike causes the victim’s heart to seize up, eventually killing them. It’s suspected that there are even more than the 20-40 reported box jellyfish deaths per year. Doctor’s may misjudge the cause of death because the symptoms can mimic other conditions.

Box jellyfish hunt their prey

Box jellyfish are curious creatures. With their two dozen eyes, they are able to see their prey very easily. Most of their 24 eyes have irises, corneas, and lenses. All this basically means is that box jellyfish can see extremely well. Regular jellyfish can only distinguish between light and dark. Box jellyfish can avoid and go after objects because of their advanced nervous system. Box jellyfish can actively go after and hunt their prey. This is very different than other species of jellyfish who have to wait for their meals to come near them. If a box jellyfish is on the hunt, they will propel through the water much like an umbrella opening and closing at speeds of four miles per hour.

The venom of a box jellyfish doesn’t release like that of a rattlesnake. Instead, box jellyfish sting and the venom is shot out. Their venom helps box jellyfish catch and digest their prey. In humans, their venom can stop your heart in less than five minutes. The venom causes holes in all of our cells and it’s very difficult to survive without immediate medical treatment.

Jellyfish to take over the sea?

Box jellyfish as a species date back at least 600 million years. These jellyfish are among the oldest species left on our planet. With ocean waters warming in recent years, box jellyfish, along with all other species of jellyfish, are growing in population. Jellyfish are thriving in conditions where other marine life can’t. Our waterways are currently being depleted of oxygen due to fertilizers seeping into our oceans. Combine that with warming temperatures and rising sea levels and a host of additional problems wreaking havoc on our waterways. Even in these environments, jellyfish are continuing to reproduce at incredible rates.

It’s hard for researchers to pinpoint the exact cause of the surge in jellyfish reproduction. Part of it may be due to the fact that we’re wiping out other big predators such as sea turtles, swordfish, and red tuna who feed on jellyfish. We’re also over-harvesting anchovies, for example. These smaller fish eat plankton and jellyfish are able to feast on all you can eat buffets. Jellyfish are eating and reproducing like wildfire.

When jellyfish attack

In recent years there have been numerous accounts of human injury, death, or catastrophes caused by jellyfish. Jellies reportedly shut down nuclear power plants in several countries because they clogged cooling equipment. During a counterterrorism exercise in the Philippines, jellyfish incapacitated 127 officers who were wading chest-deep into the water, unaware of the presence of jellyfish. Dozens of police officers were hospitalized from the incident. Most recently, a ten-ton fishing boat capsized off the coast of Japan and sank due to the 450-pound weight of jellyfish caught in their net.

Techniques to avoid and how to care for a box jellyfish sting

Some of the most common remedies for curing a jellyfish sting may actually make them worse. Traditional remedies include urinating on the skin, removing stingers, applying ice, or rinsing the bite with vinegar.  The severity of the sting will depend on the type of jellyfish, their size, the length of time you were exposed to a stinger, as well as your age and overall health. For common jellyfish stings, you may be able to treat yourself at home by soaking your skin in hot water. You can also remove the tentacle with a tweezer. For more serious stings like that of a box jellyfish, you need to seek immediate medical attention.