Transcript Echinoderms What is an echinoderm?

Echinoderms
What is an echinoderm?
•spinny-skinned animal
•Move by using hydraulic-suction cupped legs
•Found in all oceans of the world
•Hard endoskeleton (calcium carbonate)
•Radial symmetry
Quick Review…
What type of symmetry do sea stars display?
A. Bilateral
B. radial
C. Asymmetrical
A sea star can hold tightly to a surface b/c of its…
A. Madreporite
B. Eyespots
C. Tube feet
What is the skeleton of a sea star made from?
“Calcium Carbonate”
How do they move?
Water vascular system:
1. Water enters/leaves through opening called
madreporite. (exchanges gases)
2. Connected to hundreds
of tube feet (look like
small droppers)
3. Water is pushed out to
release and taken in to
grasp. (used to capture
food)
The Nervous System…
They have no head or brain.
•Contain a central nerve ring surrounding
mouth and extending down each arm.
•Sea stars contain eye spots on the ends of
their arms (rays)
•Can also detect chemicals in water
Eye Spot
Quick Review…
The water vascular system is used to do which of the
following?
a. Capture food
b. Gas exchange
c. Regulate locomotion (movement)
d. Excretion
e. All the above
f. A and C only
What is the top of the tube feet called?
a. Bulb
b. Ampulla
c. pseudopodia
Review Questions…
On a half sheet of paper, answer the questions.
They are 3 points a piece.
1.Explain how a starfish uses its arms to move.
2.Compare the symmetry of a human to that of a
starfish.
3.What are some common characteristics of
echinoderms.