Arctapodema
Arctapodema is a genus of deep-sea hydrozoans in the family Rhopalonematidae.
Description
All Arctapodema species are characterized by a small hemispherical bell of up to 23 mm in diameter. 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.Species
Arctapodema ampla Vanhöffen, 1902Arctapodema antarctica Vanhöffen, 1912Arctapodema australis Vanhöffen, 1902Arctapodema macrogaster Vanhöffen, 1902Besides the four accepted species of Arctapodema reported within the Southern Ocean, one more has been discussed. Arctapodema tetragonia 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.