1. Echinoderms Phylum Echinodermata, from the Greek for spiny skin

2. Phylum Echinodermata –spiney-skinned animals • includes sea stars, brittle stars, sea urchins, sand dollars, sea cucumbers, and crinoids • reverted back to radial symmetry • tube feet and water vascular system

3. Echinoderms

4. Subphylum Asterozoa • Classes • Asteroidea (sea star) • Ophiuroidea (brittle stars)

5. Subphylum Echinozoa Classes • Echinoidea (sea urchin and sand dollar) • Holothuroidea (sea cucumber)

6. Subphylum Crinozoa • Crinoidea (feather stars and sea-lillies)

8. Characteristics Adult echinoderms possess radial symmety

9. Class Asteroidea Sea star

10. Bat star

11. Brittle star Class Ophiuroidea

12. Sea urchin Class Echinoidea

13. Purple urchins

14. Class Echinoidea Sand-dollar

15. Sea cucumber Class Holothuroidea

16. Feather star Class Crinoidea

17. Characteristics • Echinoderms' larvae are ciliated, free-swimming organisms that are bilaterally symmetrical

18. Characteristics • echinoderms do not possess an external skeleton. • a thin skin covers an endoskeleton made of tiny calcified plates and spines • Echinoderms possess a unique water vascular system, a network of fluid-filled canals that function in gas exchange, feeding, and secondarily in locomotion • echinoderms possess a complete digestive tube • Many echinoderms can regenerate. Some sea stars are capable of regenerating lost arms. In some cases, lost arms have been observed to regenerate a second complete sea star. • the seastar can insert its stomach through the opening of a bivalve and release gastric juices, digesting the prey alive during feeding

19. Echinoderm means spiny skin