For scientists, however, jellyfish are fascinating research subjects – they play important roles in the marine ecosystem and are a key source of food for some fish and sea turtles. Some even protect commercially valuable species, such as oysters, from predators.
Can jellyfish feel pain? Jellyfish are one big neural network and respond to stimuli. So while they don't feel the same type of pain other animals do, they do know to remove themselves from bad stimuli.
Jellyfish sting their prey with their tentacles, releasing a venom that paralyzes their targets. Jellyfish don't go after humans, but someone who swims up against or touches one — or even steps on a dead one — can be stung all the same. While jellyfish stings are painful, most are not emergencies.
The tentacles, with their stinging cells, serve as defense and as a powerful weapon for capturing prey. When they come into contact with their victims, the nematocysts (cells loaded with poison) present in the tentacles release their harpoons or filaments and release a toxic substance that paralyses the prey.
Their skin is so thin that they can absorb oxygen right through it, so they don't need lungs. They don't have any blood so they don't need a heart to pump it. And they respond to the changes in their environment around them using signals from a nerve net just below their epidermis — the outer layer of skin.
Can jellyfish feel pain? Jellyfish don't feel pain in the same way that humans would. They do not possess a brain, heart, bones or a respiratory system. They are 95% water and contain only a basic network of neurons that allow them to sense their environment.
The pain radiates from the sting site and starts to itch, burn and throb as it blisters. Scratching it, though, can make the pain worse, because rubbing activates the nematocysts, which release more venom.
When you brush against a tentacle, tiny triggers on its surface release the stingers. The tube pierces the skin and releases venom. It affects the area of contact and may enter the bloodstream. Jellyfish that have washed up on a beach may still release venomous stingers if touched.
They identified how the stinging cells, called nematocytes, which are found along the tentacles of sea anemones and jellyfish — both types of cnidaria — detect and filter diverse cues from the environment to control when (and when not) to sting.
Though jellyfish do not have a brain, they are incredibly smart and adaptable. For more than 500 million years, they've been bobbing around almost all the world's oceans, both close to the water surface as well as in depths of up 700 meters. The jellyfish is the world's oldest animal.
After a while and looking at my watch's timer, I blurted out to the group: “48 minutes.” Now we learned that jellyfishes could survive that long out of sea water.
On average, jellyfish will live anywhere from 1-3 years. However, certain species will only live a few days while others are able to live for a few decades. However, scientists are unable to say definitively how long jellyfish live due to their complex life cycles.
Jellyfish stings can be painful to humans and sometimes very dangerous. But jellyfish don't purposely attack humans. Most stings occur when people accidentally touch a jellyfish, but if the sting is from a dangerous species, it can be deadly. Jellyfish digest their food very quickly.
For instance, the gobies are "miraculously" immune to a jellyfish's nasty sting. They've even been seen resting on the organisms's bells, or main body parts, as well as swimming among jellyfish tentacles, Braithwaite said. (See a picture of the deadly box jellyfish.)
Jellyfish are found in every ocean around the world and prefer to live in coastal areas. Some jellyfish are harmless to humans but others have venom that can be very deadly. The box jellyfish is one of the most venomous animals on the planet!
Once these adhere to your skin, they can continually pump toxin through your skin into the subcutaneous tissue," says Dr. Boniface. Dr. Michael Boniface says that you should never pick up a dead jellyfish.
“They can still sting you, though,” revealed our guide, Dale. “So watch out for the sensitive parts of your body—like, don't go kissing the jellyfish!”
Peeing on a jellyfish sting can actually cause stinging cells to release even more venom. (That has to do with urine being mostly water, an issue we'll cover in a moment.) “Jellyfish stings are painful enough without amplifying the symptoms,” says Dr. Waters.
At the sting site there is a characteristic raised red line that remains for hours to days. There is good evidence immersing someone in hot water works when treating bluebottle stings. Hot water inactivates the jellyfish toxins and so stops the pain; it is effective in about 90% of cases after 20 minutes.
Dr. Boniface says he recommends warm or hot water emersion because cold water can encourage nematocysts to pump more toxin into the skin. Most jellyfish stings will get better with home treatment.
The Aurelia Aurita, known as the moon jelly, is the most common and widely recognized jellyfish species. Though it has venom, it is harmless to humans—it's even a popular dish in China! The umbrella on the Aurelia Aurita can reach 30 to 40 centimeters, with marginal tentacles and gonads arranged in four circles.
Not only that, but they also have no brain, blood, lungs, or heart. Instead of a brain, jellyfish have an elementary nervous system with receptors that detect light, vibrations, and chemicals in the water.
While mammals and birds possess the prerequisite neural architecture for phenomenal consciousness, it is concluded that fish lack these essential characteristics and hence do not feel pain.