Write down four main characters of Annelida.

Characters of Annelida:

(i) They are triploblastic, metamerically segmented and coelomate animals.

(ii) These animals are found in a variety of habitats– fresh water, marine water as well as land.

(iii) They exhibit organ-system level of body organisation and bilateral symmetry.

(iv) A closed circulatory system is present.

Examples- Nereis, Pheretima (Earthworm) and Hirudinaria (Blood sucking leech).