ECHINODERMS

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ECHINODERMS

• THE SPINY SKINNED ANIMALS

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CHARACTERISTICS

• EXAMPLES sea star (starfish), brittle stars, sea
  urchins, sand dollars, sea cucumbers, sea lillies
• 6000 species have been classified
• HABITAT Saltwater, shallows to deep ocean, coral
  reefs
• FEEDING Most eat mollusks (sea star) some are
  herbivores (sea urchins), and detritus feeders
  (sea cucumber)

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SEA STAR ANATOMY
CENTRAL DISK
MADREPORITE
SPINES
RAY
ANUS
TUBE FEET
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SEA STAR ANATOMY
CENTRAL DISK
MADREPORITE
SPINES
RAY
ANUS
TUBE FEET
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SEA STAR ANATOMY
CENTRAL DISK
MADREPORITE
SPINES
RAY
ANUS
TUBE FEET
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SEA STAR ANATOMY
CENTRAL DISK
MADREPORITE
SPINES
RAY
ANUS
TUBE FEET
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SEA STAR ANATOMY
CENTRAL DISK
MADREPORITE
SPINES
RAY
ANUS
TUBE FEET
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SEA STAR ANATOMY
CENTRAL DISK
MADREPORITE
SPINES
RAY
ANUS
Pyloric Cecum
TUBE FEET
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FUNCTIONS OF STRUCTURES

• CENTRAL DISK- center of animal, provides
  attachment place for arms
• RAYS- the arms of the sea star (most have 5)
• MADREPORITE-Small disk on dorsal side. It is the
  opening to the water vascular system
• SPINES- part of the skeletal system. Used for
  protection
• ANUS- Found on the dorsal side. Waste is expelled
  here.
• BODY CAVITY- contains the internal organs

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SEA STAR ANATOMY
STOMACH
TUBE FEET
PYLORIC CECUM
RADIAL CANAL
RING CANAL
MOUTH
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SEA STAR ANATOMY
STOMACH
TUBE FEET
PYLORIC CECUM
RADIAL CANAL
RING CANAL
MOUTH
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SEA STAR ANATOMY
STOMACH
TUBE FEET
PYLORIC CECUM
RADIAL CANAL
RING CANAL
MOUTH
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SEA STAR ANATOMY
STOMACH
TUBE FEET
PYLORIC CECUM
RADIAL CANAL
RING CANAL
MOUTH
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SEA STAR ANATOMY
STOMACH
TUBE FEET
PYLORIC CECUM
RADIAL CANAL
RING CANAL
MOUTH
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SEA STAR ANATOMY
STOMACH
TUBE FEET
PYLORIC CECUM
RADIAL CANAL
RING CANAL
MOUTH
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FUNCTIONS OF STRUCTURES

• STOMACH- found inside the central disk. Flips
  inside out to digest prey
• PYLORIC CECUM- Digestive glands that produce
  digestive enzymes (2 in each ray)
• RING CANAL/RADIAL CANAL- Parts of the water
  vascular system. Transports (water,oxygen, food,
  and waste)
• TUBE FEET- used for movement, feeding,
  respiration. (2 rows on each ray)
• MOUTH- entrance to the digestive system (ventral
  side)

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SEA STAR FEEDING

• FOOD- Bivalves (Clams, oysters, scallops), coral
• METHOD- Uses its tube feet to pry open the
  bivalve. It then flips its stomach inside out
  and dumps digestive enzymes into the bivalve.
  The bivalve is digested inside its own shell.
  The sea star then flips its stomach back inside
  its mouth.

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SEA STAR REPRODUCTION

• SEXUALLY- Sperm and eggs are released into the
  open water. After fertilization the larva
  settles to the ocean bottom and undergoes
  metamorphosis into a mature seastar
• REGENERATION-If pulled into pieces, each piece
  can grow into a new sea star as long as it
  contains a portion of the central disk and has
  enough reserved food.