Conasprella sieboldii  Conasprella sieboldii, common name Siebold's cone, is a species of sea snail, a marine gastropod mollusk in the family Conidae, the cone snails and their allies. Like all species within the genus "Conasprella", these cone snails are predatory and venomous. They are capable of "stinging" humans, therefore live ones should be handled carefully or not at all. The size of the shell varies between 51 mm and 129 mm. This marine species occurs off Japan and Taiwan.