1. Phylum Echinodermata Sea stars sea lilies sea urchins feather stars
Echinoderms are __________, ________, __________, ________, ____________, _____________ and ____________.
Sea stars
sea lilies
sea urchins
feather stars
sea cucumbers
sand dollars
brittle stars
* Echinoderm means _______________. All echinoderms have spiny skin.
spiny skin

2. Echinoderms five They live in the ocean!
There are ______ characteristics of echinoderms.
five
All echinoderms have:
Spiny skin
An internal skeleton (endoskeleton)
Five-part radial symmetry
A water vascular system
Tube feet

3. Characteristics of Echinoderms
* All echinoderms have __________. Some of them have small hair-like spines, like the starfish.
spiny skin
* Some echinoderms have long spines, like the sea urchin.

4. Characteristics of Echinoderms
* The internal skeleton of an echinoderm is made of _______________________.
bony plates that are bumpy or spiny.

5. Characteristics of Echinoderms
* An echinoderm’s water vascular system is _________________________________.
a system of tubes that act as circulatory and respiratory systems
* The water vascular system also helps an echinoderm _____.
move
* The system opens to the outside through the sieve like madreporite.

6. Madreporite Opening to the outside
Connects to a ring canal around the mouth
5 radial canal extend up the arms from the ring canal

7. Characteristics of Echinoderms
* Echinoderms have __________.
tube feet
* An echinoderm’s tube feet are used for _________________________________.
moving and for getting food

8. Characteristics of Echinoderms
*Five-part radial symmetry.
*They have no anterior or posterior end and lack ______________.
cephalization
* But the bodies are 2-sided. Mouth side is the oral surface & the opposite side is the aboral surface.

9. Plan for the Day Review unifying characteristics of Echinoderms
Examine 5 classes of the Phylum Echinodermata
Check your understanding activity
* Mollusc & Echinoderm test - WEDNESDAY

10. 5 Classes of Echinoderms
Asteroidea
Echinoidea
Ophiuroidea
Holothuroidea
Crinoidea

11. Class Asteroidea * A sea star is able to re-grow its arms
* Carnivores: use tube feet to move and to open bivalves to eat

12. Class Echinoidea Sea urchins & sand dollars
* Have solid plates surrounding their internal organs
*Most are detritivores or grazers.

13. Sea Urchins spines tube feet
* Sea urchins have longer and sharper ________ that they use to protect themselves.
spines
* Sea urchins have a mouth hidden under its body and they eat sea algae (kelp).
* A sea urchin is not very active. Sometimes, it does move slowly using its __________. When not moving it uses its feet to stick to the ocean floor.
tube feet

14. Class Ophiuroidea Brittle Stars
* Have slim, flexible arms, and can move quickly. Can detach an arm if being attacked!
* Filter feeders and detritivores that come out at night

15. Class Holothuroidea Sea cucumbers * Feed on detritus
* Can expel all their internal organs as a decoy if being attacked!

16. Class Crinoidea Sea lilies & feather stars * Oldest echinoderms
* Filter feeders: attach to the seafloor by a stock and use their tube feet to catch prey

17. Echinoderms: Form & Function
Feeding
Respiration
Circulation
Excretion
Response
Movement
Reproduction

18. Feeding Sea urchins: five-part jaw to eat algae
Sea lilies: tube-feet to trap plankton
Sea cucumbers: eat sand & detritus on the ocean floor or filter feed
Sea stars: tube-feet to pry open mollusks shells. Evert their stomach into the mollusk shell and secretes digestive enzymes. Brings stomach and digested food back inside. (digests externally)

19. Respiration & Circulation
**Water vascular system** - primary system
Carries oxygen, food and wastes
*Tube-feet allow some diffusion through thin walls for respiration (gas exchange)
*Skin gills are present in some echinoderms for gas exchange
*Sea cucumber: pumps water in and out of its anus to provide oxygen to its respiratory trees

20. Excretion
Nitrogen-containing wastes are excreted through thin-walled tube feet
Digestive wastes (feces) are released through the anus

21. Response Primitive nervous system (no brain)
Nerve ring surrounding the mouth connects to radial nerves to the body segments
Senses: to detect light, gravity and chemicals

22. Movement
Tube feet ! – All use tube feet to move (water-vascular system) - hydraulics
Sand dollars & sea urchins move their spines
Sea stars & brittle stars move arms because of flexible joints
Sea cucumbers move using muscular wall & tube feet

23. Reproduction External fertilization
Eggs produced in ovaries & sperm produced in testes
Gametes released into the water for fertilization
Larvae are free swimming

24. Reproduction Regeneration
Sea stars can regenerate: must contain part of the centre ring

25. Echinoderm Ecology Urchin Barren: created by overpopulation of urchins
Sea stars are predators and help control the growth of mollusks (mussels) & corals

26. Echinoderm Ecology
Threat to coral reefs: sea star called crown-of-thorns
Feeds on coral and has destroyed coral reefs in Australia

27. Review Questions .