1. Echino = “spiny” Dermis = “skin”

2. Some different echinoderms

3. Unifying Characteristics
Spiny Skin
Internal Skeleton – “endoskeleton”
Water vascular system
Muscular tube feet (suction cup feet)
Pentaradia Symmetry
5 rays of symmetry

4. Water Vascular System
Madreporite - sieve-like opening to the water vascular system

5. Water Vascular System Functions: Respiration Circulation Movement
Ring & Radial Canals
Tube Feet
Circulation
Movement

6. Tube Feet
Each tube foot is basically a suction cup, muscles pull up the centre of the cup causing suction
Many feet working together can exert huge force, allowing “walking” and attacking

7. Groups of Echinoderms Sea Urchins and Sand Dollars Brittle Stars
Grazers and Detrivores
Solid plates protect internal organs
Brittle Stars
Filter feeders and Detrivores
Slender/Flexible arms – detach and distract
Sea Cucumbers
Detrivores
Eviscerate themselves as defence!
Sea Stars
Predatory
Regenerative if dismembered!
Sea Lilies and Feather Stars
Filter Feeders
Feather dusters of the sea

8. Sea Urchins and Sand Dollars
Grazers and Detrivores
Solid plates protect internal organs

9. Brittle Stars Filter feeders and Detrivores
Slender/Flexible arms – detach and distract

10. Sea Cucumbers
Detrivores
Eviscerate themselves as defence!

11. Sea Stars
Predatory
Regenerate if dismembered!

12. Sea Lilies and Feather Stars
Filter Feeders
Feather dusters of the sea