Limnomedusae

Limnomedusae
Olindias formosa
Scientific classification
Kingdom:	Animalia
Phylum:	Cnidaria
Class:	Hydrozoa
Subclass:	Trachylinae
Order:	Limnomedusae
Genera
See text

The Limnomedusae are an order of jellyfish in the class Hydrozoa.

Taxonomy

The taxon was created by Kramp in 1938 to accommodate certain families of jellyfish with biphasic life histories. It includes genera with medusae with ecto-endodermal statocysts and with gonads alongside their radial canals, and also genera which have polyps that are not covered by a theca. Molecular analysis performed by Collins in 2006 has since shown that the Limnomedusae are not monophylic. The family Armorhydridae, which contains a single genus and a single species, Armorhydra janowiczi, is found living in coarse sediment, has hollow tentacles and has no radial canals. It seems to share few morphological features with the other families and probably belongs elsewhere. The inclusion of Microhydrulidae is also dubious. The medusa stage is not known and the tiny polyp has no tentacles nor mouth.

Genera

The World Register of Marine Species currently lists these families and genera:

• Family Armorhydridae
  • Genus Armorhydra Swedmark & Teissier, 1958
• Family Microhydrulidae
  • Genus Microhydrula Valkanov, 1965
  • Genus Rhaptapagis Bouillon & Deroux, 1967
• Family Monobrachiidae
  • Genus Monobrachium Mereschkowsky, 1877
• Family Olindiidae
  • Genus Aglauropsis Mueller, 1865
  • Genus Astrohydra Hashimoto, 1981
  • Genus Calpasoma Fuhrmann, 1939
  • Genus Craspedacusta Lankester, 1880
  • Genus Cubaia Mayer, 1894
  • Genus Eperetmus Bigelow, 1915
  • Genus Gonionemus A. Agassiz, 1862
  • Genus Gossea L. Agassiz, 1862
  • Genus Hexaphilia Gershwin & Zeidler, 2003
  • Genus Keralic Khatri, 1984
  • Genus Limnocnida Günther, 1893
  • Genus Maeotias Ostroumoff, 1896
  • Genus Mansariella Malhotra, Duda & Jyoti, 1976
  • Genus Nuarchus Bigelow, 1912
  • Genus Olindias Mueller, 1861
  • Genus Scolionema
  • Genus Vallentinia Browne, 1902