Do jellyfish have live birth

Jellyfish do not give birth in the normal sense. The process of releasing jellyfish ephyra into the marine column is called strobilation.

Early in the life cycle of a jellyfish, it takes the form of a tiny stalk attached to the seafloor, and at that point it is called a polyp. The unattached end of this stalk forms a disk shaped bud, that is eventually shed by a process of fission. This process continues until dozens more of these little disks (ephyras) are released.

This type of reproduction is obviously asexual, since each ephyra is a clone of the others, yet a jellyfish is also sexually reproduced, when, near the end of the adult medusa stage of life, a jellyfish releases gametes into the water column to randomly join another gamete from another individual jellyfish.