EchinodermataBy Eryia & Amp
General CharacteristicsSpiny skinInternal skeletonWater-vascular
systemDeuterostomesSymmetrical animalsThey have many small, movable
extensions of the water-vascular system called tube feet.
AdaptationsThe echinoderm will change its body shape from
bilaterally symmetrical to radically symmetrical, and in the
process, settle down on the sea floor.
They crawl slowly along the ocean floor which allows them to
move from place to place.
3 Interesting FactsStarfish do not have blood.They also have
tube feet which allows them to move.Not all starfish have 5
CLASSIFICATIONTaxonomists divide the 7,000 species of
echinoderms into six classes. Here are a few..
Class CrinoideaIncludes : sea lilies and feather starsIn both
types of crinoids, five arms extend from the body and branch to
form many more arms- up to 200 in some feather star species.The
mouth faces up in crinoids, while in most other echinoderms the
mouth faces toward the sea bottom.Cilia on the arms transport
trapped food to the crinoids mouth at the base of the arms.
Class OphiuroideaThe 2,000 species of basket stars and brittle
stars make up the largest echinoderm class.Members of this class
are distinguished by their long, narrow arms, which allow them to
move more quickly than other echinoderms.Basket stars and brittle
stars live primarily on the bottom of the ocean, often beneath
stones or in the crevices and holes of coral reefs.
Class AsteroideaThe sea star, or starfish belong to this class.
They exist in a variety of colors and shapes.Sea Stars are
economically important because they prey on oysters, clams, and
other organisms that humans use as food.
Kingdom: AnimaliaPhylum: EchinodermataClass: AsteroideaOrder:
SpinulosidaFamily: AcanthastGenus: Acanthaster Species: Planci
Crown-of-thorns starfishHabitat: The Great ReefsFood Source:
coral polyps. Size:40 mm in diameter
Royal sea star
Kingdom: Animalia Phylum: EchinodermataClass: AsteroideaOrder:
PaxillosidaFamily: AstropectinidaeGenus: AstropectenSpecies:
Royal Sea StarHabitat: tropical coral reefs Food Source: algae
Size: under in. to over 3 ft. in diameter.
Kingdom: AnimaliaPhylum: EchinodermataClass: CrinoideaOrder:
ComatulidaFamily: AntedonidaeGenus: AntedonSpecies: bifida
Antedon bifidaHabitat: rocks, sedentary animalsFood Source:
algaeSize: in. to over 3 ft. in diameter.
Is it eaten by humans ??
Yes!!!!!, they are. Humans usually stay away from them but in
countries like Japan, they are eaten.
Does human pollution affect it?
Yes they are affected by the human pollution. Sewage discharge
and urban runoff has been what's most affecting these starfish
VocabularyWater-vascular system: a network of water-filled
canals inside their body.Tube feet: small, movable extensions of
the water-vascular system, which aid in movement, feeding,
respiration, and excretion.Ossicles: an endoskeleton composed of
calcium carbonate plates.
Susan, and I. Edward.Alcamo. ModernBiology.Austin, TX: Holt,
Rinehart and Winston, 2002