Arctapodema

Arctapodema
Scientific classification
Kingdom:	Animalia
Phylum:	Cnidaria
Class:	Hydrozoa
Order:	Trachymedusae
Family:	Rhopalonematidae
Genus:	Arctapodema Dall, 1907
Species
see text
Synonyms
IsonemaMaas, 1906

Arctapodema is a genus of deep-sea hydrozoans in the family Rhopalonematidae. ^[1]

Description

All Arctapodema species are characterized by a small hemispherical bell of up to 23 mm in diameter. ^{[2] [3]} Furthermore, they are characterized by four simple lips, no gastric peduncle, eight narrow radial canals with gonads on them that are adjacent to the manubrium, numerous alike tentacles in a single row, and free club-shaped marginal statocysts. ^{[2] [4]}

Species

• Arctapodema amplaVanhöffen, 1902
• Arctapodema antarcticaVanhöffen, 1912
• Arctapodema australisVanhöffen, 1902
• Arctapodema macrogasterVanhöffen, 1902

Besides the four accepted species of Arctapodema reported within the Southern Ocean, one more has been discussed. Arctapodema tetragonia (Vanhöffen, 1912) is an unaccepted species debated to be A. ampla due to its comparable morphology: a short stomach and four short lips, but four kidney-shaped gonads on the walls of stomach that are adjacent to the subumbrella, and about 112 tentacles. ^[5]

Invalid species

• Arctapodema antarcticum(Vanhöffen, 1912) [incorrect gender suffix]
• Arctapodema australeVanhöffen, 1912 [incorrect spelling]

References

1. "WoRMS - World Register of Marine Species - Arctapodema Dall, 1907". www.marinespecies.org. Retrieved 2018-02-07.
2. Kramp, P. L. (1961). Synopsis of the Medusae of the World.
3. O'Sullivan, David (1982). A guide to the Hydromedusae of the Southern Ocean and Adjacent Waters. Kingston, Australia: Department of Science and Technology, Antarctic Division. p. 136. ISBN   978-0-642-88699-6.
4. Bouillon, Jean (2006). An introduction to Hydrozoa. Paris: Publications scientifiques du Muséum. ISBN   978-2-85653-580-6.
5. Vanhöffen, E. (1912). DIE CRASPEDODEN MEDUSEN DER DEUTSCHEN SÜDPOLAR-EXPEDITION 1901 - 1903 (in German). Berlin: G. Reimer.