1. Echinoderms

2. Phylum Echindermata Share common features with chordates
Radial Cleavage
Deuterostomes (Blastopore becomes anus)
Development of true coeloem
Usually slow moving or sessile
Usually are radially symmetrical
Body parts usually radiate from center (frequently as 5 spokes)
Possess a thick calcium plate endoskeleton surrounded by a thin skin layer
Possess a unique Water Vascular System, which continues throughout animal and extends into extensions called Tube Feet.
Functions for locomotion, feeding, & gas exchange.
Reproduce sexually or through regeneration.

3. Class Asteroidea Include sea stars
Usually have 5 (or multiple of 5) arms radiating from central disk
Tube feet located underneath each arm used for locomotion & grasping prey. Operate by hydraulic principles.

4. Anatomy of a Sea Star

5. Feeding
Feed on mollusks by pulling shells apart and extending stomach outside the mouth into the bivalve. The bivalve is digested within it's shell. The sea star than re-ingests its stomach

6. Reproduction Can reproduce sexually by releasing sperm and egg.
Can reproduce by regeneration

7. Sea Stars

8. Class Ophiuroidea Include Brittle Stars
Distinct central disks with long tube-like arms
Lack suckers
Move by serpentine motion of their arms

9. Brittle Star

10. Class Echinoidea Include Sea urchins & sand dollars
Lack arms, but possess tube feet
Many species of urchins possess poisonous spines used for defense

11. Echinoideans
Sand Dollar
Sea Urchin

12. Class Holothuroidea Include Sea cucumbers
Are elongated along oral-anal axis
Lack spines and have reduced endoskeleton.
Do possess tube feet and water vascular system

13. Sea Cucumber

14. Class Crinoidia Ancient class of animals Include sea lilies
Filter feeders with arms radiating from mouth
Most are sessile, but some can move

15. Crinoids