1. Echinoderms

2. Echinoderm Facts Major Characteristics:
spiny skin
radial symmetry (symmetry around a central point)
No segmentation
Over 5000 species in 5 major classes
Sea stars
Sea urchins & Sand dollars
Brittle stars
Sea lilies and feather stars
Sea cucumbers

3. What fish is asked to sign autographs?
Stars in the Sea
What fish is asked to sign autographs?
A starfish!

4. Habitat/Location
Sea stars are found in the subtidal zone to the deepest part of the ocean.

5. Major Characteristics of Sea Stars
5 (or multiples of 5) arms radiating from a central body

6. Protection
Endoskeleton – an internal skeleton connected to the spiny skin of sea stars; gives support and protection

7. Sea Star Movement Uses tube feet with suction disks on the ends
Water vascular system pumps water into the tube feet causing them to extend

8. Sea Stars and Bivalves
They use their tube feet to pull the shells apart; this can take several hours

9. Sea Star Feeding Digestion in sea stars
Sea stars turn their stomachs out through the mouth
food is digested externally
Digested food particles are brought back into the sea star where nutrients are absorbed

10. Sea Urchins

11. Sea Urchin Basics
Spines are attached to an internal skeleton and are moveable.
Found in shallow, tropical waters
Has a mouth called Aristotle’s lantern that slowly scrapes algae off rock surfaces

12. Predation & Protection
The spines are used for defense as well as to wedge urchins into spaces between rocks.
Some animals like the sea otter are immune to the toxin in the spines. Otters use a rock to crack open the urchin on its belly.

13. Cucumbers on the Sea Floor
Sea cucumbers
Feed by enlarged tube feet grabbing microscopic organisms from the water
Breathe by taking in and releasing water
Lost the endoskeleton and spines characteristic of echinoderms. They only have small bony pieces on the skin.
When disturbed by a predator, the sea cucumber can release its digestive organs for the predator to eat while it escapes. The organs will regenerate later on.
Sea cucumbers are also a food item found on special day menus in Chinese culture. It is considered a disease preventer and longetivity tonic.