Obelia is an invertebrate marine animal that belongs to the phylum Cnidaria.
The animal first appears as a polyp, which is a tentacled form with a stalk-like shape that resembles a little sea anemone and is linked to the ocean floor or another solid surface.
Obelia alternates among sexual and asexual kinds of generations.
Polyps asexually produce medusae, while medusae asexually produce polyps.