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ECHINODERMS
CREATED BY:
Chris, MacKenzie, Amelia
General Characteristics
Habitat
• Marine-bottom of deep sea trenches,
sand, rubble, and coral reefs
Body Plan (symmetry)
• They have a radial body plan
Body Systems
Digestive
What do they eat?
• Plants, animals, tiny bits of food found on ocean
floor and in the water
How do they get their food?
They have a mouth
Describe how a sea star eats a clam: they turn
their stomach outside their body and use their
feet to pry open the shell and insert their
stomach into the clam and then secrete
digestive enzymes
Respiratory
Describe the water vascular system
including the tube feet:
Tube feet are tiny filled tubes help gather
food, and aid in their movement. They
can be stretched out, have suckers in
rows on the bottom of their feet.
Circulatory
• What is the role of the water vascular
system in the circulation: it pumps water
through the body functions in feeding and
gas exchange
Excretory
• What kinds of waste do echinoderms
produce? Liquid, and solid
• Describe how these waste are eliminated
from the body of an echinoderm: through
the anus, and through the tube feet
Response/Nervous
• What is the nerve ring and a nerve net?
• A nerve net is a group of nerve cells that
make a tissue called a nerve net
• A nerve ring is a central ring of nerves that
branches into each of the arms
• What type of sensory cells do
echinoderms have? What does each
detect? Eyespots- allows them to detect
light
Skeletal and Muscular (Movement)
• Describe the skeleton of an echinoderm:
• It has an endoskeleton, which is
composed of individual plates called
ossicles
• How is the water vascular system involved
in movement? Through their tube feet they
stretch out their limbs and then use the
suckers on the bottom of their feet to move
across the ocean floor
Reproduction
Describe asexual reproduction in echinoderms: a
star fish can asexually reproduce a arm is cut off
with a piece of the nerve ring
Describe sexual reproduction in echinoderms:
males and females release their eggs, and
sperm into the water.
Describe the larvae of an echinoderm:
Free floating larvae feed on plankton, they have
bilateral symmetry until they mature into their
adulthood
Groups of Echinoderms
• Sea Stars
• The mouth lies underneath the body in the
middle
• Brittle Stars
• Can have more than five arms, small disk and
long thin arms
• Sea Lilies and Feather Stones
• Most ancient and primitive, mouth located on
upper surface
Groups of Echinoderms… cont.
• Sea Urchins And Sand Dollars
• Do not have arms, some are ball shaped
• Sea Cucumbers
• Can be short and wide or long and thin
• No arms, mouth at one end, the mouths have
tentacles
• Sea Daisies
• Disk shaped, no arms, and have tube feet
Importance's of Echinoderms
• To Ecosystem
• They signify change in their environments, they
do that by dieing. They are intolerable of change
• To Humans
• Fisher men often cut starfish up when found in
or on nets, this causes the starfish to grow in
mass numbers
Bibliography
Blaxland,Beth. Sea Stars.sea Urchins, and their Relatives. Philadelphia: Chelsea House Publisher, 2005
Johnson, George B. Biology Principles and Explorations. Austin, Texas. Harcourt classroom education
company, 2001.
Zubi, Teresa. “Echinoderms.” Inverebrates. 15 April 2008. 18 April 2008.
<http:www.starfish.ch/reef/echinoderms.html>.
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