Life cycle of <i>Tripedalia cystophora</i>.

<p>Schematic diagram illustrating the life cycle of <i>T. cystophora</i>. The planula larva settles on the bottom and undergoes the first metamorphosis into a sessile primary polyp with two tentacles. The primary polyp grows into a fully grown polyp that usually possesses from 7 to 9 tentacles. At this stage much asexual reproduction takes place (not shown). Under optimal conditions the grown polyp undergoes the second metamorphosis and forms juvenile medusa with four primary tentacles. Sexual maturity of the medusae is reached in approximately three months. Fertilization is internal and the diagram shows a pregnant female with bell completely filled by larvae and an adult male with ripe spermatophores (orange spheres).