Transcript Invertebrates

Two Coelomate Lineages
Protostomes
Deuterostomes

Mollusks

Echinoderms

Annelids

Chordates

Arthropods
Cleavage Patterns
Protostome embryo
(spiral cleavage)
Blastopore becomes
mouth
Deuterostome embryo
(radial cleavage)
Blastopore becomes
anus
In-text figure
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Phylum Mollusca

Representative
organisms:


Coelomates


snails, slugs, oysters,
clams, octopuses,
squids
Have a true coelom
Protostomes:

Blastopore becomes
mouth
Phylum Mollusca

Body plan has 3 main
parts:



Muscular foot used for
movement
Visceral mass
covering the internal
organs
Mantle covers the
visceral mass (may
produce a protective
shell)
Cuttlefish Body Plan
Closed circulatory system with heart and
accessory heart
esophagus
digestive
kidney stomach
gland
Figure 25.22
Page 429
brain
arm
jaw
tentacle
mantle
reproductive internal
siphon
ink sac heart accessory organ
shell
radula
anus
gill
heart
Phylum Annelida



Representative Organism:
earthworm
Annelids have segmented
bodies
Metanephridia (similar to
kidneys)


Worms are hermaphrodites


Remove wastes from the
blood
Produce both sperm and eggs
Setae provide traction for
burrowing in the soil

Earthworms eat their way
through the soil
33-23-EarthwormLocomot-B. mov