1. By: Kiran Basava Isabelle Nievera
Annelida
By: Kiran Basava
Isabelle Nievera

2. Annelida
Means “little rings” which resembles the annelids body, which is a series of fused rings.
Live in the sea, freshwater habitats, and damp soil.

3. Classes Oligochaetea (earthworms) Polychaeta Hirudinea (Leeches)
Oligochaetea (earthworms)
Polychaeta
Hirudinea (Leeches)

4. Body Cavity
Present
Have a true coelom, a body cavity completely lined by tissue derived from mesoderm

5. Body Symmetry bilateral symmetry

6. Nervous System
A brain-like pair of cerebral ganglia above and in front of the pharynx
A ring of nerves around the pharynx that connects to a subpharyngeal ganglion, from which a fused pair of nerve cords runs posteriorly.

7. Circulatory System Have a closed circulatory system 5 pairs of hearts
Blood vessels circle esophagus and pump blood

8. Digestive System Unsegmented digestive tract
Mouth Pharynx Esophagus Crop Gizzard Intestine Anus

9. Excetory System
Annelida have excretory organs called nephridia, directly remove waste from the bloodstream
In earthworms (class Oligochaeta), waste is used to fertilize the soil

10. Locomotion/Musculature
Each segment of an earthworm is surrounded by a longitudinal muscle that coordinates with a surrounding circular muscle to allow an earthworm to move
Polychaetes have parapodia (“almost feet”) to move, and polychaetes and leeches can swim

11. Skeletal Type
None, their bodies are composed a a series of fused segments with muscles

12. Sensory structure/features
Have tactile organs (touch), taste buds, photoreceptor cells, and some have eyes with lenses
Palps and antennae are located on the head (tactile)
Also have lateral organs- epidermal sensory cells that are responsive to light or touch

13. Reproduction Hermaphrodites
Cross fertilize by aligning to exchange sperm, which is stored while an organ called the clitellum makes a cocoon that receives the eggs and sperm from the worm, and remains in the soil while embryos develop.

14. Gas Exchange
Earthworms have many tiny blood vessels in their skins, which function as their respiratory organs
The blood has hemoglobin that carries oxegen.
In leeches, most gas exchange occurs through the body wall

15. Unique Characteristics
Easily recognized due to segmented bodies
Most segments have the same internal structures repeated throughout the worm
Leeches used to be used for blood letting, and today are used to drain blood that accumulates in tissues after injuries or surgeries

16. QUESTION #1 What type of body cavity do annelids have? Coalomate
Pseudocoelomate
Acoelomate
none

17. Answer
A. COELOMATE

18. QUESTION #2
An annelid’s circulatory system includes how many pairs of hearts? 6 9 1 5

19. ANSWER
D. 5

20. QUESTION #3 Describe the skeletal type of annelids.
They have an exoskeleton.
The do not have one.
They have a cuticle
They have a hydrostatic skeleton.

21. ANSWER
B. They do not have one

22. QUESTION #4 How do earthworms exchange gas? Diffusion They do not.
They have many tiny blood vessels in their skins, which function as their respiratory organs

23. ANSWER
C They have many tiny blood vessels in their skins, which function as their respiratory organs