1. Phylum Annelida

2. Phylum Annelida Characteristics Protostomia, eucoelomates
Metamerism (= unspecialized segmentation)
In the Classes:
Parapodia
Clitellium

3. Systems
Integument- epidermis is one cell layer with mucous gland that secrete a moist cuticle.
Skeletal -hydrostatic (using coelom)
Muscle- longitudinal and circular muscles Each segments muscles are independent of the other segments.
Digestive- complete, complex, with typhlosole for absorption and chloragogen cells acting as digestive gland and excretory cells.

4. Systems (continue) Excretory- a pair of nephridia per segment.
Respiratory -through skin, some through parapodia; tubeworms have gills.
Circulatory- closed system, use hemoglobin as oxygen carrier.
Nervous- dorsal brain; ventral, double, solid nerve cord, with ganglia in each segment.
Endocrine- hormones secreted by nervous system.
Reproductive-
Dioecious in Polychaeta; no special organs, posterior end becomes gonads.
Monoecious in Oligochaeta and Hirudinea; Clitellium.

5. Annelida Taxonomy Phylum Annelida (an-nel-i-da) Earthworm dissection
Click on any term that is underlined to go to that slide
Phylum Annelida (an-nel-i-da)
Class Polychaeta (poly-key-ta)
Nereis, Aphrodita, Chaetopterus, Arenicola, Amphitrite
Class Oligochaeta (ol-e-go-key-ta)
Lumbricus, Tubifex
Class Hirudinea (hi-ru-din-e-a)
Hirudo, leech
Earthworm dissection

6. Return to taxonomy
Nereis (clam worm)
Nereis
Nereis

7. Return to taxonomy
Aphrodite (sea mouse)
dorsal
ventral

8. Other Polychaetes Return to taxonomy Amphitrite (plum worm)
Chaetopterus
Arenicola (Lug worm)

9. Hirudo (leech)
Return to taxonomy

10. Lumbricus
Return to taxonomy
dorsal
ventral
clitellium
Lumbricus

11. Earthworm Dissection
Return to taxonomy
Cross section

12. Earthworm cross section
Return to taxonomy
Earthworm cross section