Jellyfish are very ancient creatures. They have existed for hundreds of millions of years. However, jellyfish are relatively low-level organisms, so some organs that other animals have do not exist in jellyfish. For example, jellyfish have no brain, so their IQ is not particularly high. But instead of just swimming with the current as biologists had expected, they are smarter than they were.
For example, in the course of observation, the researchers found that when jellyfish swim, if they find some obstacles such as sand or sandbanks, they will sink, and then sink into the deeper water, and then stay in that place. In addition, jellyfish also have a high degree of salinity in the water, allowing them to avoid the fresh water formed by melting glaciers. In addition, jellyfish also like to gather together in groups to carry out activities or prey activities.
As mentioned above, jellyfish do not have brains, but they have a nervous system. Many people would think that brainless creatures probably don't need to rest. But in fact, this view is wrong, after many experiments, researchers found that even if jellyfish do not have a brain, their nervous system also needs to rest. In fact, not only jellyfish, but also other brainless organisms need rest. During the rest of the jellyfish, they may be suspended in the water, generally static, but sometimes move with the current. Researchers also tested the reaction speed of jellyfish and found that jellyfish react more slowly when they sleep.
