New deep sea terebellid polychaete with sucker like ventral pads adapted to a sediment free environment

A new species of terebellid polychaete, Lanice spongicola sp. nov., is described from deep-sea sponges in the northwestern Pacific Ocean off Minamidaito Island, Okinawa, Japan. This species is associated with the sponge Walteria cf. leuckarti at a depth of 843 m. It is characterized by a deeply grooved, sucker-like mid-ventral pad on segments II-VI, three pairs of arborescent branchiae, distinct notochaetae and neurochaetae morphology and arrangement, and its ecological association with sponges. The anterior area of ventral pad is used as an adhesion organ, facilitating attachment to the host sponge. This species is a terebellid that differs from the typical sediment-dwelling lifestyle, having adapted to a sediment-free environment through a relationship with sponges and the development of specialized sucker structures for attachment.