1. By: Sierra Mushett, Jay Burns
Phylum Annelida
By: Sierra Mushett, Jay Burns

2. Digestive System

4. Organs
PHARYNX- this is where food enters and is swallowed by the worm.
CROP- this is where food is stored.
GIZZARD- this is where food is ground up by stones that the earthworm has eaten.
INTESTINE- glands in the intestine aid in digestion, this is where the food is absorbed and taken to the rest of the body.

5. Reproductive System

7. Reproductive Organs CLITELLUM- secretes a sac that holds the eggs
SEMINAL VESICLES- stores sperm
SEMINAL RECEPTACLES- used to communicate by testis sacs
OVARIES- this is where ova is arranged for development
TESTES- these produce sperm

8. The reproduction in these worms can be either asexual or sexual.
The asexual is by fragmentation, budding, budding, or fission.
The eggs of terrestrial forms start off in cocoons and hatch as miniature versions of the adults.
The eggs usually develop into free- swimming larvae.
Their ability to regenerate lost body parts is highly developed in many from polychaetes and oligochaetes.

9. Circulatory System

10. Circulatory Organs
AORTIC ARCHES- pump blood into the dorsal and ventral blood vessels, similar to a human heart
DORSAL BLOOD VESSEL-carries blood to the front of the earthworm’s body
VENTRAL BLOOD VESSEL- carries blood to the back of the earthworm’s body

11. Nervous System

12. Nervous Organs
GANGLIA “BRAIN”- The brain connected to the ventral nerve cord
VENTRAL NERVE CORD- provides movement throughout the length of the worm

13. The nervous system also typically consists of a primitive brain, or ganglionic mass, which is located in the head region.
The nervous system consists of a single or double nerve running along the ventral side of the body.
Active annelids such as the earthworm have larger ganglia in the head region that serve as simple “brains”.
The organs used for sensing generally include eyes, taste buds, tactile tentacles, and organs of equilibrium called statocysts.

14. Excratory System

15. Excretory Organs
NEPHRIDIA (METANEPHRIDIA)- collects fluid from the coelom and nephridiopore, nutrients and water are reabsorbed through this process. Waste is left behind and excreted.

16. External Structure

17. External Organs
SETAE- bristles that help control the worm while moving through soil
CUTICLE- the outermost layer of the worm,usually covered in cilia

18. Sources
invertebrates/annelida

19. APA Citations
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Earthworms. (n.d.). Retrieved March 24, 2017, from
Annelida. (n.d.). Retrieved March 24, 2017, from
Wilkin, P. D., & Blanchette, J. (2016, August 29). CK-12 Foundation. Retrieved March 24, 2017, from
Annelid. (n.d.). Retrieved March 24, 2017, from