Species of Helicoradomenia, the genus to which most aplacophoran vent species belong, occur on northern and southern segments and at the Galapagos Rift.
Individual aplacophoran sclerites are covered by a cuticle as they are extruded from the forming epidermal cell (Haas 1981), a cuticle not related to the formation of the cuticular body mantle.
Early development of the aplacophoran mollusca Chaetoderma.
The digestive tract of Helicoradomenia (Solenogastres, Mollusca), aplacophoran molluscs from the hydrothermal vents of the East Pacific Rise.
Comparison is made to the aplacophoran genus Helicoradomenia, with the same diversity but with fewer species.
Helicoradomenia belongs to the neomenioid aplacophorans, which are narrow or wide cylinder-shaped molluscs ("wormshaped" in the literature) covered by aragonite sclerites held by body mantle cuticle--the scleritome.
Most aplacophorans are carnivorous, but a few feed on detritus.
All aplacophorans, except for some brooders, seem to have planktonic lecithotrophic larvae (some perhaps demersal), determined from (1) egg size in the gonads (e.
1) The single most important genus of hydrothermal aplacophorans in number of species is the endemic neomenioid Helicoradomenia.