About 5,400 species of often brightly colored marine worms are included in the annelid class Polychaeta. Worms of this class have a head with short sensory projections and tentacles and a segmented body covered with many setae, or bristles. They range in length from less than 1 inch (2.5 cm) to approximately 10 ft (3 m) long. Found worldwide, polychaetes perform the important function of turning over sediment on the ocean floor. What is the deepest point at which polychaetes have been observed? Discuss
Source: The Free Dictionary