Jellyfish don’t have legs, but they have tentacles. The number of tentacles they have varies wildly, as some species only have 15, while others might have thousands.
Jellyfish don’t move around using their tentacles or legs. They will use their muscles to push off a pocket of water from underneath the bell to gather momentum, which will help them move around.
Jellyfish don’t require legs to move and they will use their tentacles for feeding and for moving around.
Do Jellyfish Have Legs or Tentacles?
Jellyfish have tentacles, not legs. Some jellyfish species only have a dozen of these tentacles, while larger jellyfish might have thousands of tentacles.
The main role of the tentacles for jellyfish is to help them with feeding. These tentacles are armed with stinging cells that will harm the target that the jellyfish are looking to eat.
Sometimes, these cells can be harmful to humans and they can cause severe damage, depending on the species.
These stinging cells are called cnidocytes. These stinging cells will release venom which will cause severe damage to the target. While most jellyfish won’t harm you with their tentacles, the venom of some jellyfish can be potentially deadly.
As such, jellyfish thus don’t have legs, but they have tentacles instead. Many people believe that the structures on their bodies are legs, but these are actually tentacles.
They don’t need legs to move around because they do so by contracting the muscles within their body to push the water away.
How Many Tentacles Do Jellyfish Have?
Some jellyfish species only have 12-15 tentacles, while other species might have thousands of them. The number of tentacles will vary wildly.
For example, the Box jellyfish, which is usually spotted in Australia, only has 15 tentacles. Even though these have fewer tentacles, they have a very potent venom that can cause serious problems, and might even be deadly to some people on some occasions. Fewer tentacles don’t mean that the jellyfish is less dangerous.
On the other hand, you will also find some species with a thousand or more tentacles. One such example is Lion’s mane jellyfish, which has around 1200 tentacles. This type of jellyfish is one of the largest jellyfish in the world and it will use its tentacles to hunt and kill its prey.
These tentacles can be several feet long – the largest case was found in 1870, where the jellyfish had tentacles that were 120 feet long. With the help of these long tentacles, these jellyfish will be able to hunt much deeper, and thus, they’ll have an abundance of food that will help them sustain themselves.
Most jellyfish, though, will have a number of tentacles that are somewhere in between those two extremes. Some have a few dozen, while others might have hundreds of tentacles. It will massively depend on the habitat of the jellyfish and its surroundings, as well as its feeding habits.
Why Do Jellyfish Have no Legs?
Jellyfish have no legs because they don’t need them, and they have tentacles that will do most of the work for them instead of using their legs. For movement, they will use the muscles on the bell to generate it.
If you consider animals that have legs, you’ll see that the primary role of the legs is to move around. Legs are mostly found in animals that live on land, while they are much rarer than animals that live in the sea.
Jellyfish belong to the latter category. For moving around in the sea, they don’t require legs. Instead, they make use of the movement of the water and the resistance that it offers.
They’re very good at floating around and moving with the flow to find their prey, as they move into directions where prey is, such as plankton.
Most of the movement is also generated by the muscles in the bell of the jellyfish. These muscles will cause their bodies to contract and expand, which will push pockets of water away from the jellyfish. In turn, this will help the fish generate movement and move around in the water.
Some jellyfish have a variety of different tentacles that might resemble legs, but they aren’t legs. These thicker tentacles might be used for stinging or for catching larger types of prey.
Read Also: Do Fish Eat Snakes?
What Do Jellyfish Use their Tentacles For?
The primary role of these tentacles for jellyfish is for hunting their prey, but also for self-defense.
Jellyfish will use their tentacles to hunt down their prey. They will mostly eat smaller fish, plankton, and even smaller jellyfish. With these tentacles, they will try to ensnare as much smaller animals inside and then consume these animals using these tentacles. Sometimes, they need to use the tentacles to kill their prey.
Another huge reason why the tentacles are so important for jellyfish is for self-defense. They need to defend themselves with these tentacles as they float around, especially if they encounter larger predators.
The sting of the jellyfish might be deadly to some animals and even to humans. When they sting, jellyfish will release venom that will severely harm the attacking animal, even if the animal wasn’t trying to attack it. This often happens to humans who get stung by jellyfish because the fish thinks of the human as a threat.
Some jellyfish have extremely long tentacles that can be dozens of feet long. With them, they will try to reach as deep down into the ocean to get as much food, making the jellyfish highly territorial.
Read Also: Dead Fish Spiritual Meaning and Symbolism
To conclude, jellyfish don’t have legs, but rather, they have tentacles. Using these tentacles, the jellyfish will hunt their prey and protect themselves. These tentacles have stinging cells on them, which the jellyfish will use for self-defense and for attacking other animals.
They also don’t need legs because legs would impair their movement in the water. Instead, jellyfish move around using their muscles in the bell, which will help them push the water away and create a movement that way.
Stuart is the editor of Fauna Facts. He edits our writers’ work as well as contributing his own content. Stuart is passionate about sustainable farming and animal welfare and has written extensively on cows and geese for the site.