Does a jellyfish have an incomplete digestive system?

No, jellyfish do not have an incomplete digestive system. They have a complete digestive system, consisting of a mouth, pharynx, gastrovascular cavity, and anus.

The mouth, located on the underside of the jellyfish's bell, leads to a pharynx, which then connects to the gastrovascular cavity. This large, centrally-located cavity functions as both a stomach and an intestine, where food is digested and absorbed.

Undigested material is eventually passed out of the body through the anus, which is located on the oral surface of the jellyfish.