DEUTEROSTOME ANIMALS

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DEUTEROSTOME ANIMALS

• COELOMATE ANIMALS
• ANUS BEFORE MOUTH

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DEUTEROSTOME ANIMALS

• TWO MAJOR PHYLA
• ECHINODERMS
• CHORDATES

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ECHINODERMATA

• ANIMALS WITH SPINY SKIN

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ECHINODERMATA

• DEFENSIVE SPINES ON SURFACE
• ALL MARINE - BOTTOM DWELLERS
• ENDOSKELETON OF CALCIUM CARBONATE (limestone)
• SYMMETRY
• RADIAL AS ADULTS ACTUALLY PENTARADIAL
• BILATERAL AS LARVA
• UNDERGO METAMORPHOSIS

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ECHINODERMS

• FREE LIVING ORGANISMS
• SOME SYSTEMS WELL DEVELOPED
• OPEN CIRCULATION
• EXCRETION THROUGH OUTPOCKETS BY DIFFUSION
• NERVE RING W/ RADIAL NERVES
• RESPIRATION BY DIFFUSION
• SEXES SEPARATE

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ECHINODERMS

• UNIQUE WATER VASCULAR SYSTEM
• USED FOR LOCOMOTION
• SEIVE PLATE
• STONE CANAL
• CENTRAL RING CANAL
• RADIAL CANALS
• AMBULACRAL GROOVE
• AMPULLA
• TUBE FEET

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Figure 25.40bPage 331
sieve plate
ring canal
ampulla
Water vascular system
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ECHINODERM CLASSIFICATION

• ASTEROIDEA STARFISH
• CRINOIDEA SEA LILLY, SEA FAN
• OPHIUROIDEA BRITTLE STAR
• ECHINOIDEA SEA URCHIN SAND DOLLAR
• HOLOTHUROIDEA SEA CUCUMBER

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STARFISH

• VENTRAL MOUTH
• EVISCERATE TO FEED ON BIVALVES
• CARDIAC STOMACH INSERTED INTO BIVALVES SHELL
• 5 PR. DIGESTIVE GLANDS RELEASE ENZYMES
• PYLORIC STOMACH SOAKS UP NUTRIENTS
• ABORAL ANUS

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STARFISH

• REPRODUCTION SEXUAL
• 5 PAIR OF GONADS
• EXTERNAL FERTILIZATION

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Figure 25.40aPage 441
upper stomach
ossicle
gonad
spine
anus
lower stomach
coelom
digestive gland
eyespot
spine
ossicle
Body plan of a sea star
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ECHINODERMS EVOLUTIONARY MILESTONE

• DEUTEROSTOME
• ENDOSKELETON