[2] The British marine biologist Edgar Johnson Allen first described this worm in 1904, giving it the name Poecilochaetus serpens.

Behind the head are two long palps which can be extended forward, or coiled loosely, and which may be half the length of the body.

[3] Poecilochaetus serpens forms a U–shaped burrow in sand, the tube being lined by particles of clay or mud cemented with mucus; digging is performed by the head using the parapodial cirri attached to the first segment and associated long bristles.

[3] A water current is drawn through the tube by undulations of the body and fan-like movements of the parapodia and bristles.

The worm probably feeds on plankton and organic particles removed from the water current, and diatoms have been found in its gut.