WBotrynema brucei is a common mid-water Arctic hydrozoan, of the family Halicreatidae.
WBotrynema ellinorae is a species of hydrozoan in the family Halicreatidae.
WHalicreatidae is a family of hydrozoans. The family comprises 6 genera and 9 species.
WAeginura grimaldii is a species of deep sea hydrozoan of the family Aeginidae. It is found in the north-eastern Atlantic Ocean, Pacific Ocean, and the Arctic Ocean. It has a depth range of 660-1200m deep. Live specimens are bright reddish in color, with pale tentacles, and a light red globous capsule dome containing the dark colored red body. It usually measures no more than 4.5cm from the peak of the bell to the end of the tentacles.
WHalicreas minimum is a species of deep sea hydrozoan of the family Halicreatidae. It is the only species in the monotypic genus Halicreas.
WHalitrephes maasi, commonly known on the internet as the firework jellyfish, is a species of deep sea hydrozoan of the family Halicreatidae. The most recent account of the jelly has been found at a depth of 4,000-5,000 feet near the Revillagigedo Archipelago off Baja California Peninsula, Mexico.
WHomoeonema platygonon is a species of deep sea hydrozoan of the family Halicreatidae. It is the only species in the monotypic genus Homoeonema.