Marine worm

An example of a marine worm, the Parborlasia corrugatus lives at depths of up to 4,000 metres.

Any worm that lives in a marine environment is considered a water worm. Marine worms are found in several different phyla, including the Platyhelminthes, Nematoda, Annelida (segmented worms), Chaetognatha, Hemichordata, and Phoronida. For a list of marine animals that have been called "sea worms", see sea worm.