Campanulariidae

Campanulariidae is a family of animals in the phylum Cnidaria, or stinging celled animals. Campanulariidae is comprised entirely of hydroids, a Greek term meaning "Water Animals" applied to the plant-like polyp colonies of the class Hydrozoa. The family Campanulariidae includes a variety of species in the genus Obelia, genus Laomedea, genus Clytia, and genus Campanularia. All species of Campanulariidae are aquatic in habitat, primarily inhabiting coastal regions and tidal pools.

The Obelia are probably the most well known species of this phylum, and include four species. All are around 20-35cm in height with a series of branches carrying the individual polyps. One species, Obelia longissima, is unique for its ability to produce Obelin, a photoprotein which allows for bioluminscence.

The genus Laomedea inludes such species as Laomedea angulata and Laomedea flexuos, which are similar in appearance to the Obelia, though are smaller and lack a medusae stage present in Obelia.