Jellyfish are transparent and usually sink after death. There are also the most plankton in the sea, and they will decompose the body quickly.

Jellyfish’s body is 95% water.

Many people think that jellyfish only live in the ocean, but in fact they are found in some freshwater lakes and ponds. Jellyfish is rich in collagen and is widely used in the food industry. Some people also use jellyfish to treat rheumatoid arthritis. When a jellyfish faces an enemy, it first relies on its transparent body to hide in the background of the ocean. If this fails, the venomous sting on its body will be its main defense method. The earliest jellyfish appeared 650 million years ago. After so many years of evolution, they still have no brain, five senses, heart, or bones. 95% of their bodies are water. Once they leave the water, they will die soon.

Jellyfish will turn into water after death. It turns out to be true. Most of the body of a jellyfish is water. After death, other substances that make up the body will be decomposed by aquatic organisms or dissolved in the water, so it looks like water after death.

There are two ways of movement of jellyfish. One is to suck someone into the body and then spray it out from behind to push the body forward. Another way is to float on the ocean currents and migrate with the ocean currents. In fact, they have a third way, which is to move around the world with the ship's ballast water. This method allowed them to quickly occupy all oceans in just over 100 years. For example, the "immortal jellyfish" is native to the North Pacific and has now overrun the Mediterranean.