How do jellyfish muscles and mesoglea work together during swimming?

In jellyfish (medusae), swimming is achieved through a rhythmic interaction between muscle contractions and the elastic properties of the mesoglea.12

The process functions as follows:

• Contraction: The musculoepithelial cells located on the concave, subumbrellar surface of the bell contract. This action reduces the diameter of the bell, squeezing the subumbrellar space and forcing out a stream of water, which propels the animal via jet propulsion.12
• Elastic Recoil: Once the muscles relax, the mesoglea—which acts as a resilient skeleton—functions like a spring. Its natural elasticity causes the bell to return to its original shape, re-extending the muscle fibers in preparation for the next stroke.12
• Steering: While circular muscles provide the primary force for swimming, the contraction of radial muscles can distort the bell's shape, allowing the jellyfish to direct its water jet and steer through the water.2

This cycle of contraction and elastic recoil allows medusae to perform rhythmic swimming movements.1