Introduction to the Annelida

Everybody's favorite, worms. . .

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, sea mice, and "EWWW! I stepped on that THING!"

Annelids can be told by their segmented bodies. Polychaetes (meaning "many bristles") have, predictably, many bristles on the body, while earthworms and leeches have fewer bristles. There are about 9000 species of annelid known today.


Click on the buttons below to learn more about the Annelida.


An Annelid Worm Biodiversity List is available, with links to a large number of annelid-related resources of all sorts. It also includes subscription information on the ANNELIDA e-mailing list.

Serious annelid connoisseurs should not miss the Biodiversity and Biological Collections Web Server. Those interested in vermiculture might prefer The Burrow, a remarkably designed Website with abundant information on earthworm farming. And not to forget the third main class of annelids, Mark Siddal's Hirudinea pages present original work on the evolution of leeches.