Phylum Echinodermata: Sand
Dollars, Starfish, and Sea Urchins
By: Amanda Brainerd
Key Characteristics
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Endoskeleton
Five-part radial symmetry
Water-vascular system
Skin Gills
No head or brain
Anatomy
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Sieve
Ring canal
Tube feet
Anus
Stomach
Digestive glands
Skin gills
Reproductive glands
Digestion
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Simple digestion
In through mouth and down esophagus
Two-stomach system
Intestines
Anus
Respiration
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Water vascular system
Tube Feet
Skin Gills
Bumps or Spines on surface
Hemolymph
Circulation
Internal Transport
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Water vascular system
Madreporite
Ring Canal
Water
Tube Feet
Excretion
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Anus
Mouth
Tube feet and skin gills
No real excretion system
Diffusion
Response
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Eyespots
Nerves
Tube Feet
Spiny Skin
Statocysts
Movement
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Tube and thin layers of muscles
Tube feet
Water vascular system
Suckers and arms
Spines
https://www.youtube.com/watch?v=cec4YPXBnXk
Reproduction
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Diecious
Sexual Reproduction
External fertilization
Fission and regeneration
Larvae settle on ocean floor
Examples
Facts
 Echinodermata has approximately 7000 described
living species and about 13,000 extinct species known
from the fossil record.
 Brittle Stars can be found at depths as great as 6000
meters.
 Sea stars have up to 200 light sensitive eye spots.
 Some species can live up to 10 years.
 Echinoderms are the most complex of invertebrates.
Words Cited
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http://echinodermsg.blogspot.com/2007/04/digestion.html
http://intro.bio.umb.edu/112s99Lect/bodyplans/starfish.html
http://echinodermsf.blogspot.com/2007/04/internal-transport.html
http://www.mesa.edu.au/echinoderms/
http://www.oceaninn.com/the-nature-preserve/echinoderms/