A new genus and species
Amembranaster dimidatius and two new species from the genus
Pteraster are described from the Kurilo-Kamchatskii trench. The material was collected during the 14th, 39th and 59th expeditions of the R/V "Vityaz" from the depth of 6156-7260 m.
Amembranaster gen. n. is characterized by the total reduction of supradorsal membrane and aperture papilaes. Two new speices,
Pteraster texius sp. n. and
P. ifurus have a partially reduced supradorsal membrane and partially reduced membranes of transverse series of adambulacral spines. This is the first discovery of
Pteraster at ultraabyssal depths.