jellyfish is a kind of lower creature, so their body structure will seem relatively simple. For example, they have no legs like other animals, only tentacles. In the process of observing jellyfish, we can often see that they are moving with the current. But jellyfish don't just drift with the current, they also have some ability to move autonomously, but in a different way from most animals.
For jellyfish to move, they need to shrink their lumens. The contraction and expansion of the jellyfish cavity can affect the flow of water in and out. When their cavities are expanded, water is sucked into the jellyfish's body. When the situation is reversed, that is, when the internal organs shrink, the water will be ejected out of the body. Jellyfish rely on the force generated by these currents to move freely. In addition, sometimes jellyfish need to change their direction in the process of movement, at this time they may use their tentacles, in fact, this part is also an important part of their activities.
As mentioned above, jellyfish can not only move with jellyfish, they can also move themselves, but their way of movement is quite special. Jellyfish move by ejecting water through the contraction of their cavities. Their muscle fibers, which are necessary for squeezing the lumen, are distributed throughout the jellyfish's body. In addition, in the process of jellyfish activities, its tentacles can also play a certain role.
