Mollusks belong to invertebrates, but invertebrates include more than mollusks, and it cannot be considered that all invertebrates belong to mollusks. Although mollusks include many species, they are relatively consistent in some physical characteristics, such as their bodies are generally flexible, most of them have shells, there are no body segments in their body structure, and they may have arms and feet. Although jellyfish belong to invertebrates, they are not mollusks. Jellyfish have a simpler body structure and belong to a lower class of organisms than mollusks.
As mentioned above, although jellyfish are also invertebrates, they are not mollusks, but a lower animal. Specifically, jellyfish belong to coelenterates, and coelenterates belong to invertebrates. Coelenterates also include many species, some of which are common features, such as coelenterates are generally radiosymmetric, for example, they may have a nervous system and so on. Jellyfish are basically in line with these common characteristics, they are radiosymmetric, and they also have a nervous system, and their nervous system is relatively developed.
Coelenterates are inferior to mollusks. The same is true of jellyfish, their body structure is very simple, there are some organs and structures jellyfish do not have, such as the heart, such as the brain system.
