?Polydora websteri Hartman 1943
Rare, non-indigenous, pest
Robust, 30 mm for 100 segments
Prostomium weakly bilobed. 2 pairs of eyes in juveniles that may be lost. No pigmentation on body, only 2 continuous black lines along the edge of the feeding groove on the palps. Occipital antenna absent. Falcate spines on chaetiger 5 alternating with companion chaetae. Spines are broad/thick with subterminal lateral flange or sheath but no tooth. Bidentate hooded hooks begin on chaetiger 7, hooks constricted at shaft and up to 11 hooks per ramus, number of hooks decreasing posteriorly. Branchiae start on chaetiger 7. Pygidium wider than posterior chaetigers, saucer-shaped with a distinct dorsal notch.
South Africa: Northern Cape, Western Cape and Eastern Cape provinces.
East and west coasts of USA (Type locality Connecticut), Hawai’i, Australia, New Zealand, Japan, Korea, Brazil, Venezuela, Mexico
Only boring into farmed oysters(Crassostrea gigas) shells in South Africa but are known not to be host specific.
Molecular evidence and distribution indicates that it is alien. Identity needs to be clarified.