Segmented worms make up the Phylum Annelida. The phylum includes earthworms and their relatives, leeches, and a large number of mostly marine worms known as polychaetes. Various species of polychaete are known as lugworms, clam worms, bristleworms, fire worms and sea mice. Annelids can be told by their segmented bodies. Polychaetes have many bristles on the body, while earthworms and leeches have fewer bristles. There are about 9000 species of annelid known today. The basic annelid form consists of multiple segments, each of which has the same sets of organs.