1. 7th Grade Biology Chapter 11 Section 2 Page 386
Annelids
7th Grade Biology
Chapter 11 Section 2
Page 386

2. Annelids Segmented worms! Phylum Porifera Kingdom Sponges Animal
Look at figure 17 pg 348, discuss how they are different than sponges, (animal kingdom has 30 phylums)
Phylum
Platyhelminths
(Flatworms)
Phylum
Nematoda
(Roundworms)
Phylum
Annelida
(Segmented worms)

3. Segmented Worms Kingdom Animal Phylum Annelida (Segmented Worms) Class
Polychaeta
(Marine Worms)
Class
Hirundinea
(Leeches)
Class
Oligochaeta
(Earthworms +)

4. Earthworms (Class Oligochaeta)
Each body segment has four pairs of setae
Two sets of muscles for movement
Round muscles
Long muscles
Well developed digestive system
Closed circulatory system
Small Brain
Hermaphrodites

5. Setae: bristlelike structures on the bodies of earthworms used for movement

6. Setae

7. Digestive System Mouth Pharynx (Throat)-muscular for food intake
Esophagus-tube which takes food to crop
Crop- Sac used for food storage
Gizzard- muscular structure that grinds soil and organic matter
Intestine - absorbs nutrients moving them into the blood
Anus - wastes are excreted
Nephridia- help filter waste out of blood

9. Digestive Organs

10. Circulation and Respiration
Closed circulatory system-moves blood through vessles
Aortic arches-- heartlike structure that pumps blood thru earthworms body.
Dorsal blood vessel on top Ventral blood vessel on bottom
Oxygen and carbon dioxide is exchanged through the skin.
figure 9 pg 370

11. Nervous System
Small brain or ganglia is made up of a mass of nerve tissue
Nerves in each segment join to form a main nerve cord that connects to the brain
Pg 370

12. Reproductive System Hermaphrodites Cannot fertilize their own eggs
Seminal Vesicles- location of sperm production
Seminal Receptacle-where sperm is received during copulation
Add more earthworm photos

13. Earthworm Mating
Get new photo!!!!

14. Reproductive Organs

15. Other Parts
Clitellum- swelled gland 1/3 of the way down the earthworm that releases material for earthworm cocoons

16. Earthworm Benefits Help recycle nutrients in the soil
Help aerate the soil ( move estimated pounds per acre of soil each year)
Food source for other animals

17. Leeches Kingdom Animal Phylum Annelida (Segmented Worms) Class Class
Polychaeta
(Polychaetes)
Class
Hirundinea
(Leeches)
Class
Oligochaeta
(Earthworms +)

19. Leech Facts Feed on blood of other animals
Use anesthetic, so you do not feel the bite
Can suck 2-10 times it’s own weight in blood
Read leaches and medicine page 372