Aurelia jellyfish are unisexual, males releasing spermatozoa into the sea to fertilize the eggs of a female. Embryos are spawned in the mother and develop into gastrulae, or planula larvae. Once released, each larva lives on its own until it finds an appropriate surface to which it attaches, growing into a polyp known as a scyphistoma. The scyphistoma then undergoes an asexual process of fission called strobilation to produce tiny ephyrae, which will mature to become the next generation of medusae. In this stage, the scyphistoma is referred to as a strobila. The ephyrae accumulate in a stack at the oral end of the scyphistoma and are eventually released to become free-swimming individuals that will become sexually mature medusae in less than a year.