The jellyfish has many body systems, although they look quite simple. Here are the main
stuctures in a jellyfish:
The body of a jellyfish is made almost completely of water. It consists of an epidermis (on
the outside), and a gastrodermis (the thick inside layer). In between these two layers in the mesoglea, or the "jelly".
Their nervous system is quite simple compared to humans. They do not have a brain, but
they have a "nerve net", which covers their entire body. It controls the movement as well as the body functions.
In order to eat and digest food, they use their gastrovascular cavity to absorb the nutrients
out of their prey.