Tubificoides wasselli a marine oligochaete, described from the Indian River Lagoon, Delaware. Marine oligochaetes resemble terrestrial earthworms. This worm has up to 50 segments and reaches 11 mm in length. It is found from Delaware to the Gulf of Mexico. It is presumed to be native to the Northwest Atlantic. In the Northeast Pacific, it has been collected from San Francisco Bay (1961-1962) and Victoria, British Columbia (before 1979). It is presumed to be introduced to the West Coast. Possible vectors include solid ballast, ballast water, or plantings of Eastern Oysters. Oligochaetes lack parapodia and have relatively short setae. They are hermaphroditic, with a few anterior segments modified to form a reproductive section, called the clitellum. At sexual maturity, they have a few modified segments forming a reproductive section, called a clitellum. The worms copulate, and lay fertilized eggs in cocoons. Marine oligochaetes usually occur in silty or muddy sediments and are deposit-feeders.