Oligochaeta
/ˌɒlɪɡə(ʊ)ˈkiːtə
/plural noun Zoology
A class of annelid worms which includes the earthworms. They have simple setae projecting from each segment and a small head lacking sensory appendages.Annelids with a clitellum (a swelling towards the head of the animal, where the gonads are located) are classified in the Clitellata, which is further divided into Hirudinea and Oligochaeta (including the earthworms)....
- The phylum Annelida is traditionally divided into three classes: Oligochaeta, Hirudinida, and Polychaeta (marine annelids).
- In traditional classification schemes, the Annelida consists of the Polychaeta and the Clitellata (the latter including the Oligochaeta and Hirudinida).
Origin
Modern Latin (plural), from oligo- 'few' + Greek khaitē 'long hair' (taken to mean 'bristle'), because they have fewer setae than polychaetes.