1. Earthworm Dissection Lumbricus terrestris Kingdom: Animalia Phylum: Annelida

2. Students should Identify the following
Segments
Septum
Setae
Pharynx
Esophagus
Crop
Gizzard
Intestine
Aortic Arches
Ventral Nerve Cord
Dorsal Blood Vessel
Clittelum
Seminal Vesicles
Seminal Receptacles

3. Students should know the following terminology
Invertebrate
Castings
Hermaphroditic
Hydrostatic Skeleton
Closed Circulatory System

4. Students will use the following tools for the earthworm dissection
Scalpel
Probes
Dissecting Pins
Rubber Padded Dissecting Tray

5. Scalpel

6. Probe

7. Dissecting Pins

9. Before you start dissecting, find the following:
Mouth
Setae – the bristles used for locomotion. They are located by rubbing your fingers along the earthworm’s body. They are often times easier to feel than to see.
Sperm Duct
Clittelum

10. Mouth

11. Sperm Duct

12. Clittelum

13. Mouth
Pin your worm at the tip of the mouth and at its midpoint.

14. Continue your cut to the mouth
Start your incision 2 cm behind the clittelum.
Make sure not to cut too deeply.

15. Begin to separate the skin using pins

16. Pin the skin back as you go along the cut
Pin the skin back as you go along the cut. Angle your pins outward so that are out of the way.

17. As you pin the skin back, take your probe and break the partitions between the segments. These are called Septum.

19. Pharynx

20. Aortic Arches – Earthworms have 5 pair of these simple hearts.

21. Aortic Arch

22. Seminal Vesicles

23. Seminal Receptacles

24. Crop

25. Gizzard

26. Intestine
Dorsal Blood Vessel

27. Ventral Nerve Cord

28. Ventral Nerve Cord

29. Brain

30. Nerve Cord and Brain

31. Brain