Tubificoides apectinatus is a marine oligochaete, described from Halifax, Nova Scotia, as a variety of Tubifcoides gabriellae. Marine oligochaetes resemble terrestrial earthworms. This worm has 40-60 segments and is 10-20 mm long. It is found from Nova Scotia to the Gulf of Mexico. It is presumed to be native to the North 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.