What is the stem of jellyfish meme?

This is a video circulating on the Internet. In the video, a man picks up a jellyfish in the water. At the moment of picking it up, the top of the jellyfish's skull is taken off, which is called "splitting" This video has also been dubbed by the majority of dubbing enthusiasts and sand sculpture netizens, saying last words for jellyfish.

Jelly Fish (English name: Jellyfish) is an important plankton in aquatic environment, including Echinocephala, Daphnopoda, Cruciferae and Cubea. Jellyfish is a very beautiful aquatic animal.

Its shape is like a transparent umbrella, and the diameter of the umbrella is large or small. The diameter of the umbrella of the big jellyfish can reach 2 meters. There are some whisker-like tentacles on the edge of the umbrella, and some tentacles can be as long as 20-30 meters.

Exercise habit of jellyfish

Jellyfish changes the volume of the inner cavity by shrinking the shell and squeezing the inner cavity, and ejects the water in the cavity to move by spraying water. Muscle fibers extending from the top of jellyfish epidermis to the end of umbrella body control the contraction and expansion of inner cavity.

The lumen expands, and water is slowly sucked in to fill the lumen; The inner cavity shrinks rapidly, squeezing water out of the cavity, and the thrust generated by the water jet makes the jellyfish move axially along the body. ?