1. (Soft bodies, sometimes a “skeleton”, but no joints)
Echinoderms
(Soft bodies, sometimes a “skeleton”, but no joints)

2. Echinoderms Sea stars Brittle stars Sea Urchins Sea Cucumbers
& Sand dollars
Sea Cucumbers

3. Main Phyla of animals
Animal : Plant : Fungi : Protist : eubacteria : archeabacteria
Cnidaria
Echinoderms
Mollusks
Arthropods
Vertebrates
Reptiles
Cephalopods
Crustaceans
mammals
Bivalves
Gastropods
Insects
Arachnids
Bird
Fish

4. Main Phyla of animals Echinoderms
Animal : Plant : Fungi : Protist : eubacteria : archeabacteria
Cnidaria
Echinoderms
Sea star
Brittle star
Urchins
Mollusks
Arthropods
Vertebrates
Cucumbers
Reptiles
Cephalopods
Crustaceans
mammals
Bivalves
Gastropods
Insects
Arachnids
Bird
Fish

5. Why are they interesting?
They live in ALL parts of the ocean, cold hot, deep shallow
They ONLY live in the ocean
They have amazing powers of regeneration (cut them in half and they each grow back another half!)
Can do a lot… without a brain!

7. WHAT is an echinoderm? Echino= spiny Derm = skin Echinoderms have:
Water vascular system
“skeleton” of plates – no joints.

8. Water vascular system
First - hydraulics

9. Water vascular system
Hydraulics work great when you need high power and even pressure
How could you use this to turn the car?

10. Behold the natural hydraulic system Echinoderm water vascular system

11. The finesse of the tube foot

12. Sea Stars (not starfish)

13. SeaStars
The “typical” echinoderm

14. Sea Stars-What do they eat? How do they eat?
Stomach is pushed INSIDE OUT to digest stuff it can’t swallow
Sea stars are sometimes
1. Herbivores:
2. Scavengers:
3. Hunters/carnivores:
But…. How do they do this
with no brain or eye?
See one coming after a clam

15. Stomach goes out because …they have no jointed skeleton!

16. Stomach goes out to the food.

17. Sea Star Reproduction
Broadcast spawners

18. Sea Star Reproduction Star fish are either male or female
They are broadcast spawners
They have a short Larval stage during which they are just a filter feeding “plankton”
Of course, you can always just cut them in half too!

19. Brittle Stars

20. Brittle stars have “muscles”!!!! Think of them as “advanced sea stars”

21. Videos of echinoderms moving

22. Brittle stars vs Sea stars
Tube feet are not suction cups!
Movement is not via tube feet but by ‘walking” with it’s multiple “legs/arms”
Legs/arms have muscles… star fish have few muscles
There is not much else different … feeding and reproduction is similar to starfish.

23. The Sea Urchin

24. What is a sea urchin?
Take a sea star, fold its legs up so he’s a ball… make some tube feet  spins!

26. Sea Urchins have tube feet and modified tube feet/spines
Spines are moved via the water vascular system also – hardened tube feet
Tube feet all over the surface, but concentrated at base

27. Sea urchin water vascular system

28. A ball of organs … no brain

29. Sea urchins have ‘teeth” not a stomach that distends.

30. One common Texas Sea Urchin is The Sand Dollar – it filters the sand and eats what it finds!

31. The Sea Cucumber

33. Sea Cucumbers Tube shaped echinoderms Filter sediment for food
Defense mechanism is to use it’s ability of regeneration to sacrifice parts of itself to potential predators!
Reproduction all same as before!