Starfish

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Starfish Phylum Echinodermata
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Starfish Dissection
Aboral surface
Oral surface
Mouth
shell
Madreporite is opening of the water vascular
system
Tube feet are the terminal end of the water
vascular system
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Starfish Dissection
ampulla
shell
Starfish can evert their stomach through their
mouths and begin digestion of the prey outside
the body
Gonads may be big or small depending on season
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Starfish Dissection
Water Vascular System Water comes in the
madreporite, travels through the stone canal to
the ring canal and then flows through the radial
canals in each arm. The short transverse canal
connects the radial canal with the ampulla. When
the ampulla fill with water, they contract and
move the tube feet.
Ring canal
Radial canals in each ambulacral ridge
Radial canals in each ambulacral ridge
ampulla
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Phylum Echinodermata (means spiny skin)
Echinoidea sea urchins and sand dollars
Crinoidia sea lilies
Asteriodia sea stars starfish
Opiuroidea brittle stars
Holothuroidea sea cucumbers
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Phylum Echinodermata
Habitat marine Symmetry Bilateral larva,
radial symmetry in adults Body Cavity
coelomate Development Deuterostome Skeleton
spicules embedded in dermis or a calcareous
endoskeleton composed of spines/ossicles