Abstract
The hydroid and early medusa stages of the deep sea hydrozoan jellyfish Earleria purpurea (Hydrozoa: Mitrocomidae) are described. Mature medusae were collected from the Monterey Bay submarine canyon near Monterey, California, USA utilizing a remotely operated vehicle and returned to the laboratory for culturing. In vitro fertilized eggs developed into free-swimming planulae larvae that settled and metamorphosed into benthic hydroid colonies consisting of feeding hydranths and medusa producing gonangia. Newly released medusae were grown to maturity and placed on educational display at the Monterey Bay Aquarium. The hydranths and gonangia were compared and found to be distinct from those of E. corachloeae the only other member of the Genus Earleria with a described life cycle.