Diopatra is a genus of polychaete worms in the family Onuphidae.
Members of this genus live in thick, parchment-like tubes that project from the sediment on the seabed.
The tubes are covered on the outside by fragments of shell, algae, fibers and other small objects, collected by the worm and stuck in place by mucus.
Diopatra dart partially out of the tube and grasp the prey with their maxillae and mandibles.
Their large anterior parapodia help them to immobilize the prey.