Download Echinoderms

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Kingdom: Animalia
Phylum: Echinodermata
5 Classes:
Asteroidea (Sea Stars)
 Crinoidea (Sea Lilies and Feather Stars)
 Ophueroidea (Brittle Stars)
 Echinoidea (Sea Urchins)
 Holothuroidea (Sea Cucumbers)
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6,000 species
Radial Symmetry (Adults)
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Bilateral symmetry (Larvae)
Spiny skinned (where its name comes from)
Tube feet
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Controlled by water vascular system
 Water-filled system of interconnected canals and tube
feet (used to crawl along the sea floor, collect food, and
respiration)
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No heart, brain, or eyes
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Globally distributed in almost every ocean
depth
Highest diversity in:
Reef environments
 Shallow shores
 Deep ocean
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With the help of ocean currents larvae can
swim great distances and this creates global
distribution
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Asexual
Echinoderms can
regenerate missing
limbs, arms, spines and
even intestines (sea
cucumber)
Some brittle stars and
sea stars can reproduce
asexually by breaking a
ray or arm, or by
splitting the body in
half (fission)
Each half then becomes
a whole new animal
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Sexual
Release sperm and eggs
into the water
 Most species produce
pelagic (free floating)
planktonic larvae
 Larvae are bilaterally
symmetrical, unlike
their parents
 When they settle to the
bottom they change to
the typical echinoderm
features
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1,600 species
Radial symmetry (5 arms or more)
Skeleton: ossicles
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Small calcareous plates that move with one another
forming flexible joints
Live on coral reefs, sand, and rocks
Most are carnivorous and scavengers
They eat clams, oysters, coral, fish, and other animals
 Stomach extrudes over prey, digestive juices are secreted
and the tissue of the prey is liquefied
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Tube feet are important
Locomotion
 Food collection
 Respiration
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Sea lilies
80 living species
 Sessile (attached to the ocean floor)
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Feather Stars
520 living species
 Not fully sessile
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 Can crawl along the surface and swim short distances
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Unique because of mouth/anus on upper surface
Filter feeders (eat whatever they find floating by)
Feeding: pinnules wraps prey in mucous secretions, and
ciliary tracts on the groove floor then transport it toward
the mouth
Feed on plankton (that’s why they like habitats with strong
currents)
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2,000 species
Most active and fastest moving
Long slender arms (similar in looks to sea star)
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Skeleton: ossicles
Scavengers and detritus feeders
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Used for locomotion (not dependant on tube feet)
Feed on small crustaceans, plankton or worms
No anus (just digestion)
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they push out their stomachs to eat food like the sea
star does
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900 living species
Spine covered (used for protection, and some are
poisonous)
lack distinct arms
Hard skeleton: ossicles are fused (known as “test”)
Eat using Aristotle’s Lantern (located in mouth on
underside of their body, waste is sent out the anus
at the top)
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5 teeth
 Used to pull and rip algae off rocks
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Herbivores
Seaweed
 Algae
 Bits of plants and animals
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1,500 species
Soft bodies, tough and leathery skin
Skeleton: ossicles have degenerated and buried
in fleshy body
Mouth is surrounded by several tube feet that
have been modified into tentacles that capture
small organisms they eat
When threatened they can throw up their
insides and grow new ones back
Filter feeder
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Feed on plankton
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http://en.wikipedia.org/wiki/Echinoderm
http://www.bio200.buffalo.edu/labs/echinoderm
s.html
http://www.starfish.ch/reef/echinoderms.html
http://www.oceaninn.com/guides/echino.htm
http://tolweb.org/Asteroidea
http://www.allthesea.com/Sea-Cucumbers.html
http://library.thinkquest.org/J001418/urchin.htm
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http://tolweb.org/Echinodermata
http://library.thinkquest.org/26153/marine/ench
ino.htm