Larvae plankton -
The medusa stage is the dominant and conspicuous individual in the life cycle of a lot of jellyfishes. The image shows a young medusa in the free-swimming stage. The polyp-stage is sessile, living in the bottom. The medusoid body resembles a bell with the convex side upward and the mouth located in the middle of the concave under-surface. The tentacles hang down from the margin of the bell. The size is under 1 mm. The image shows a medusa turned inside out.