PHYLUM ANNELIDA

(Metamerically segmented and coelomate animals)

Prof. S D Rathod

Annelids

Soft bodied, triploblastic, bilaterally symmetrical and true coelomates

Divided into the segments called as annuli

Excretion is performed by nephridia

Nervous system well developed and has brain

Class – Polychaeta: (animals with many setae)

Setae are many form lateral parapodia

Head is distinct with sensory organs like eyes, tentacles, palps etc

Free swimming larval stage is found called as trochophore

example - Nereis

Parapodia

Heteronereis

Tube dwelling polychaetes

Arenicola Sabella

Class – Oligochaeta: ( animals with few setae) Setae few and are

arranged segmentally

Distinct head eyes and tentacles are absent

Clitellum is usually present

example - Pheretima (earthworm)

Class – Hirudinea: (Class of leeches)

Ectoparasitic and fresh water forms

Secrete an enzyme in its gut called as hirudin

33 segments Oral sucker.

Posterior sucker Anus is present in

22nd segment on dorsal side.

Leech bite

Good bye!!!!!!