Oligochaetes are asubclass of worms in thephylumAnnelida.
With around 10,000species the Oligochaetes make up about a half of the phylum Annelida. These worms usually have few chaetae or "bristles" on the outer body surface, unlikepolychaetes. The best known is thegardenearthworm.
Oligochaetes aresegmented worms and most have a spacious body cavity (coelom) which is used as a hydroskeleton. They range in length from less than 0.5 millimetres (0.020 in) up to 2 to 3 metres (6.6 to 9.8 ft) in the 'giant' species such as theGiant Gippsland Earthworm and the Mekong WormAmynthas mekongianus.
