Polydora villosa Radashevsky & Hsieh 2000

About 2 m depth.

A moderate-sized gonochoristic Polydora species boring into corals. Prostomium weakly incised anteriorly. Eyes absent. Caruncle up to end of segment 3; median antenna absent. Posterior notopodia with separate needlelike spines in addition to capillaries. Segment 5 with dorsal superior and ventral capillaries; major spines falcate with lateral tooth or flange on one side and a shelf with rough edge on the other. Branchiae from segment 7 through most of body. Pygidium small disc- or cup-shaped with dorsal gap.

West Pacific Ocean: Chin Bay, Penghu Islands (Taiwan, Taiwan Strait).

Bores into skeletons of the living scleractinian corals Porites lobata Dana, 1846, P. lichen Dana, 1846, Hydnophora exesa (Pallas, 1766), Cyphastrea chalcidicum (Forskål, 1775), and Montipora sp., at shallow water. The species makes long and U-shaped burrows, communicating with the coral surface through two or more openings. The walls of the burrows are lined up with mud, forming an internal mud tube, which extend 1-2 mm above the coral surface.