Abstract
A new family, Podosphaerasteridae, is proposed for the valvatid asteroid genus Podosphaeraster, with a new species of the genus from southern Japan, western North Pacific. Podosphaeraster differs from the fossil genus Sphaeraster and other valvatid families by the overall body form and the skeletal structure. The new Japanese species, P. toyoshiomaruae sp. nov., differs from the previously known species of Podosphaeraster principally in number and size of granules on the abactinal and actinal plates, number of adambulacral spines, retention of perforations in terminal plates, and ratio of horizontal diameter to vertical diameter. Podosphaeraster toyoshiomaruae was collected together with abundant sponges and probably lives closely associated with sponge. This is the first record of the genus Podosphaeraster from Japanese waters.
