1. Earthworms

2. Posterior / Tail End
Anus
Anterior / Head End
Clitellum
Mouth
Setae
Seminal
Receptacles

3. Seminal Receptacles Testes Seminal Vesicles Ovaries
Ganglia
Pharynx
Hearts
Seminal Receptacles Testes Seminal Vesicles Ovaries
Sperm Duct
Esophagus
Crop
Gizzard
Intestine
Dorsal Blood Vessel
Central Nerve Cord
Ventral Blood Vessel

4. Setae Appearance: Tiny bristles (feel them)
Location: Entire length of worm.
Function: Tiny hairs to help with movement + sex.

5. Clitellum Appearance: Knob Location: Near center of length.
Function: Secretes fluid to enclose fertilized eggs.

6. Mouth Appearance: Hole Location: Front / Shorter End
Function: Food intake/eating

7. Ganglia/Brain Appearance: Small flesh-colored tissue blob
Location: Directly behind mouth.
Function: Control organs + responses.

8. Pharynx Appearance: Round Lump
Location: Directly behind mouth + ganglia.
Function: Start food break down.

9. Hearts/Aortic Arches Appearance: Black finger nail clippings
Location: Behind Pharynx.
Function: Circulate blood.

10. Esophagus Appearance: Skinny tube Location: Behind Pharynx (center).
Function: Carry food to crop + gizzard.

11. Crop Appearance: Round Lump (feels like a bag)
Location: Behind hearts + reproductive organs.
Function: Food storage before digestion.

12. Gizzard Appearance: Round lump (feels muscular) Location: Behind crop.
Function: Grind up food.

13. Intestine Appearance: Long Tube
Location: Along back length (leaving gizzard).
Function: Absorb nutrients + excrete waste.

14. Dorsal Blood Vessel Appearance: Thin dark line
Location: Along back length (on top).
Function: Carry blood.

15. Ventral Blood Vessel Appearance: Thin dark line
Location: Along back length (on bottom).
Function: Carry blood.

16. Seminal Receptacles Appearance: Fleshy colored lumps/bits
Location: Behind hearts.
Function: Receive sperm for egg fertilization.

17. Seminal Vesicles Appearance: Small fleshy lumps/bits
Location: Behind hearts.
Function: Release + store sperm.

18. Ovaries and Testes Appearance: Small fleshy lumps/bits.
Location: Behind hearts.
Function: Produce eggs and sperm.

19. ---Dissection Notes---
Lie worm on its belly (rounded/darker side pointed up).
Identify clitellum.
Carefully cut from MOUTH  CLITELLUM
Carefully peel back skin.
Identify organs.

20. Dorsal Blood Vessel (Dark Line)
External Dorsal:
Mouth
Clitellum
Dorsal = top (like dorsal fin) more commonly called posterior today.
Blood Vessel = carries blood….
Dorsal Blood Vessel (Dark Line)
Anus

21. External Ventral: Mouth Sperm Ducts Clitellum Genital Setae
Clitellum: Produces mucus for reproduction
Mouth is always closest to clitellum, anus is at the other end.
Genital Setae: used to hold the worms together during mating.
Sperm Ducts: Produce sperm.
Female Genital Pores: contain egg.
Worms are hermaphrodites, but only reproduce through sexual reproduction. This allows all worms to reproduce, increasing chance of successful offspring.
Sperm Ducts
Clitellum
Genital
Setae
Female Genital Pores

22. Internal: Pharynx Esophagus Ganglia (Brain) Crop Aortic Arches
Right Side = Mouth
Cut open dorsal side (top)
Ganglia = Brain
Pharynx = food tube  esophagus
Esophagus  food tube  crop (goes underneath the heart and repr. Organs)
Crop = storage unit
Gizzard = stones + muscle contraction breaks down instestine
Intestine = useful nutrients absorbed, waste  out anus
Earthworms have 5 aortic arches (5 hearts)
Oxygen diffuses directly from air  skin  blood stream
Esophagus
Ganglia
(Brain)
Crop
Aortic Arches
Intestine
Gizzard
Seminal Vessicles
Seminal Recepticles

23. Internal w/o Digestive…
Nerve Cord (Like our Spinal Cord)
Seminal Receptacles

24. Let’s watch a demo…