1. Starfishes, sea urchins, sea cucumbers
Phylum Echinodermata
Starfishes, sea urchins, sea cucumbers

2. Higher Classification Echinodermata
Class Asteroidea – sea stars
Class Ophiuroidea – brittle stars
Class Echinoidea – sea urchins
Class Holothuroidea – sea cucumbers
Class Crinoidea – sea feathers

3. General Characteristics
Exclusively Marine
Body unsegmented
Adults with pentamerous secondary radial symmetry
Larvae bilaterally symmetrical
With unique water vascular system

4. Larval Echinoderms showing bilateral symmetry

5. Water Vascular System

6. General Characteristics cont.
First phylum with internal skeleton
With dermal calcareous ossicles
Some with spines or spicules
Digestive system complete
Respiration by dermal branchae, tube feet, or respiratory tree
No kidneys
Dioecious
Locomotion by tube feet, and/or arms

7. External Anatomy

8. Internal Anatomy

9. Brittle star anatomy

10. Anatomy of a Sea Urchin

11. Aristotle’s Lantern

12. Sea Urchin Anatomy

13. Asteroidea

14. Ophiurodea

15. Echinoidea

16. Holothuroidea

17. Crinoidea