PHYLUM ECHINODERMATA Echinoderms

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PHYLUM ECHINODERMATA(Echinoderms)

• Pages 365-368

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General Information

• Means spiny bodied animals of spiny skin
• Skeleton is made up of rigid plates of calcium on
  the outside of soft body part which compromise
  the internal skeleton
• Live only in oceans and have a WATER VASCULAR
  SYSTEM - a network of water filled vessels
  radiating from mouth area (moves water through
  the animal)

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General Information continued.

• Tube feet are like suction cups for movement
• Fossil evidence shows the sharing of common
  ancestors with vertebrates

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Physical Characteristics

• Live in marine environment nearly all live in
  the ocean
• Size varies from 1cm to 1 meter
• Radial symmetry
• Internal skeleton called an endoskeleton
• 2 parts 1. calcium plates
• 2. spines attached to
  skeleton and function in protection

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• WATER VASCULAR SYSTEM (see diagram)
• Water Pumping System
• helps the echinoderm move and get food
  and other supplies
• 1. many canals inside (stone, ring, radial,
  connecting) force water into the tube feet
• 2. tube feet connected to suction cups
• 3. water pumps through tube feet and
  creates suction
• 4. helps in movement and feeding
• movement is a crawl
• as the water pressure in the tube
  changes tube contract and relax resulting in
  movement
• no other phylum has tube feet

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Body Systems

• Lack a circulatory , respiratory, and excretory
  system
• Simple nervous system-no brain or head
• Food Getting-eat mollusks, worms, or slow moving
  animals / uses tube feet to open shells / stomach
  protrudes from body / digestion occurs externally
• Reproduction 2 sexes
• sexual? Sperm and
  egg
• 
  external fertilization
• asexual?
  Regeneration
• 5. Movement of material (food and oxygen) occurs
  by diffusion

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Examplesnearly all have spiny skin and a water
vascular system

• Starfish
• water vascular system
• eat clams How? Wraps arms around clam using
  tube feet pulls open the shell
• mouth in the middle/bottom and extends stomach
  through (uses digestive juices)
• Sand dollar see page 368 for picture
• short spines / flat
• body has spines with tube feet

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• Sea Cucumber see page 368 for picture
• has tentacles
• Sea Urchin see page 365 for picture
• shaped like a sphere
• long movable spine with tube feet
• 5. Brittle Stars see page 368 for picture