1. 08 Sept. 2014Annelida.ppt1 Phylum Annelida “segmented worms”

2. 08 Sept. 2014Annelida.ppt2 Phylum Annelida Latin “ringed” analogy to tree annual rings ~ 9000 species Body plan Tube-in-tube, Protostomous Bilateral symmetry Coelomate, “split” coelom Marine, aquatic, terrestrial

3. 08 Sept. 2014Annelida.ppt3 Phylum Annelida Tissues and organs differentiated Segmentation highly developed Mesodermal “blocks,” each with own coelom Septa between segments

4. 08 Sept. 2014Annelida.ppt4 Phylum Annelida Hydrostatic skeleton Fluid pressure in coelom provides support & locomotion Circular muscles Longitudinal muscles Peristaltic locomotion

5. 08 Sept. 2014Annelida.ppt5 Function of a hydrostatic skeleton

6. 08 Sept. 2014Annelida.ppt6 Phylum Annelida Setae (“bristles”) of chitin “anchors” for earthworm “paddles” for polychaete Enlarged as jaws in leeches, some polychaetes

7. 08 Sept. 2014Annelida.ppt7 Animal Life Ways the needs of cells are met Food O 2 and CO 2 exchange Across epidermis, some have “gills” Waste removal Metanephridia in each segment

8. 08 Sept. 2014Annelida.ppt8 Phylum Annelida Special concerns of a multicellular animal Circulation closed Coordination: Nervous system with paired ventral cords Structural support: Hydrostatic Movement: Hydrostatic Maintenance of water balance: Segmental metanephridia. Reproduction Usually sexual, sexes separate or hermaphroditic

9. 08 Sept. 2014Annelida.ppt9 Phylum Annelida Closed circulatory system Multiple “hearts” Hemoglobin not in blood cells reddish-pink color

10. 08 Sept. 2014Annelida.ppt10 Phylum Annelida Central nervous system Dorsal brain Pair of nerves on sides of esophagus Paired ventral nerve cords with paired ganglia in each segment Transverse nerves connect ganglia in each segment

11. 08 Sept. 2014Annelida.ppt11 Phylum Annelida Earthworms’ paired nerve cords are fused into single ventral cord Arthropod better illustrates primitive nervous system of both phyla.

12. 08 Sept. 2014Annelida.ppt12 Phylum Annelida Metanephridia for excretion of metabolic waste products

13. 08 Sept. 2014Annelida.ppt13 Phylum Annelida  “Class Polychaeta” Mostly marine, very diverse (polyphyletic ) “many setae,” clusters with 20+ setae parapodia

14. 08 Sept. 2014Annelida.ppt14 Phylum Annelida  Superclass Errantia Mostly marine, diverse active swimmers, predators “many setae,” clusters with 20+ setae parapodia

15. 08 Sept. 2014Annelida.ppt15 Phylum Annelida  Superclass Sedentaria Mostly marine, sedentary tube builders, filter feeders Class (?) marine tube worms Class (?) Clitellata With clitellum

16. 08 Sept. 2014Annelida.ppt16 Phylum Annelida  Class (?) Clitellata Clitellum Aquatic & terrestrial  Subclass (?) Oligochaeta Few setae in 2-4 clusters per segment

17. 08 Sept. 2014Annelida.ppt17 Phylum Annelida  Subclass (?) Hirudinea pair of bladelike “jaws” posterior “suction cup” Predators External parasites, “bloodsuckers” Secrete anticoagulants Medicinal use

18. 08 Sept. 2014Annelida.ppt18 Phylum Annelida  Class Hirudinea  Hirudin from leech, Hirudo medicinalis, inhibits blood clotting  H. medicinalis, registered as “medical device.”