In this article, we’ll answer the question:
“How do jellyfish move?”
First, you’ll find a short summary explaining the way jellyfish move through the water, then learn about how it can be possible without a brain. There’s also information on whether jellyfish actually swim or float in the ocean.
Jellyfish, also called sea jellies, are in the subphylum Medusozoa, which is a major part of the phylum Cnidaria. A jellyfish is a free-swimming marine animal with tentacle arms that contain stinging cells to capture prey.

How Do Jellyfish Move?
Jellyfish move by using the umbrella-shaped bell to create a wall of water for the jellyfish to push off and propel its body forward. The process of contracting and relaxing a ring of muscles around the bell is what causes a jellyfish to move (or swim).
How Does a Jellyfish Move Without a Brain?
A jellyfish moves without a brain by possessing a net of nerves at the base of their tentacles. This sensory structure controls motor activity in the water by sending chemical signals to the jellyfish’s muscles to contract, allowing them to move through the water without a centralized brain.
Do Jellyfish Swim or Float?
Jellyfish can both swim and float as methods for moving through water. Jellyfish swim by using the umbrella-shaped bell of their body to propel themselves forward and float with the current to drift to new locations.
According to Science.org, “these creatures are actually some of the most energy-efficient swimmers in the animal kingdom.” And, the jellies swimming technique could provide inspiration for our human underwater travel. “Engineers could design underwater vehicles that emit similar pressure, for example, boosting their efficiency as they zoom along.”
What Is the Movement of Jellyfish Called?
The movement of jellyfish is called jet propulsion. Jellyfish movements are also referred to as swimming and floating.
Learn More About Jellyfish
Now that you know more about jellyfish and the way they move, you may also be interested in these other educational guides on these sea animals:

The Way Jellyfish Move Summary
You now know how do jellyfish move.
As you discovered in this guide, jellyfish move by using the umbrella-shaped bell of its body to create a wall of water to propel itself forward. Jellyfish also float freely in the ocean without having to move any muscles.

I’m the lead editor and writer for Animal Answer Guide. I enjoy sharing expert knowledge on the various characteristics of common species within the five distinct groups of animals: amphibians, birds, fish, mammals, and reptiles.