What are the Characteristics of Phylum Annelida?

10 main characteristics of Phylum Annelida are given below:

  1. Bilaterally symmetrical and vermiform.
  2. Body has more than two cell layers, tissues and organs.
  3. Body cavity is a true coelom, often divided by internal septa.
  4. Body possesses a through gut with mouth and anus.
  5. Body possesses 3 separate sections, a prosomium, a trunk and a pygidium.
  6. Has a nervous system with an anterior nerve ring, ganglia and a ventral nerve chord.
  7. Has a true closed circulatory system.
  8. Has no true respiratory organs.
  9. Reproduction normally sexual and gonochoristic or hermaphoditic.
  10. Troch phore lava is present during indirect development.