1. Earthworm Dissection
Photo Credit: All photos taken from
Some content from:
Various videos from both and

2. External Anatomy

3. Cuticle – keeps the worm from drying out

4. Dorsal – top part

5. Ventral – bottom part

6. Clitellum- makes mucus that dries up to form a cocoon

7. Prostomium – covers the mouth of the worm

8. Mouth- opening at the end allowing the intake of food consisting of particles of both living and dead substances

9. Setae – bristle like structures that help the worm move

10. Sperm Duct – openings in which sperm can pass through

11. Sperm groove – sperm moves along here from sperm duct to another worm

12. Oviduct- tube through which eggs pass

13. Anus – where excrement (poop) comes out

14. Internal Anatomy

15. Circulatory System Dorsal blood vessel Aortic arches
Ventral blood vessel
Dorsal blood vessel
Go To Nervous System

16. Nervous System
Ganglion- group of nerves. In the earthworm, there is a pair of ganglia in each segment and a cerebral ganglia acts like a brain

17. Excretory System
Nephridium- filters wastes. Almost each segment of the worm has a pair of nephridia.

18. Digestive System Food goes from the: Mouth Pharynx Esophagus Crop
Gizzard
Intestine
Anus

19. Anus – where excrement (poop) comes out

20. Reproductive System

21. Seminal vesicles- store sperm produced by the earthworm

22. Seminal receptacles- paired organs that store sperm received from another worm during copulation

23. How do Earthworms Mate?
Earthworms are hermaphrodites which means they have both mail and female body parts

24. Worms line up head to tail

25. Slime coats the clitellum

26. As they do this the tube passes over the sperm ducts and picks up sperm

27. Down the sperm groove

28. And mixes with eggs that come out of the oviduct

29. When free of the slime tube, the cocoon closes up and the sperm and eggs mix.
This sac is carried by a worm until baby worms have developed, at which point the sac breaks open and they squirm free.