Download Molluscs

The effect of _________ on __________ of
freshwater (rams horn and pond snails) and
saltwater (common periwinkle, Littorina littorea)
Domain Eukarya
Kingdom Animalia
Phylum Mollusca
(or soft-bodied)
Phylum Mollusca
Characteristics:
*Soft-bodied invertebrate covered with protective
mantle that may or may not form a hard, calcium
carbonate shell
*Second largest animal phylum. Largest Marine phylum
*Have a muscular foot for movement which can be
modified into tentacles
*Complete, one-way digestive tract with a mouth &
anus
*Cephalization - have a distinct head with sense organs
& brain
*Have a scraping, mouth-like structure called a radula*
*Go through free-swimming larval stage called
trochophore
radula
Eastern mudsnail (Ilyanassa obsolete) or
Common periwinkle (Littorina littorea)
observation and experimentation
Get to know your subject:
• Diagram and label snail using the laptop or textbook as guide
• Make at least five behavioral observations
• State two differences among individuals in your group
Experiment:
• Create an experiment to learn something about snails in general.
• On a piece of butcher paper you will write up your findings.
Include:
• Purpose (1 sentence)
• Hypothesis (1 sentence)
• Data (table and graph)
• Conclusion (one paragraph. State WHY data is as it is)
Class 1 of 3:
Gastropods (or stomach-foot)
They include:
nudibranchs (or naked gills)
snails
limpets
chiton
Why so
bright?
Other characteristics of gastropods
• Toxic coloration
More characteristics
• Toxic harpoon
• Killer cone snail
Fun videos
• Snail egg in leg
• Snail zombies
Class 2 of 3:
Bivalves (or 2 doors)
most abundant phyla
They include:
clams
oysters
mussels
characteristics:
1. Byssal threads with cement
Characteristics:
2. Chemoreceptor tentacles
3. Eyes (can you find them?)
4. motility
Active bivalves video
Class 3 of 3:
cephalopods (or head-foot)
They include:
Nautilus
Squid
octopus
cuttlefish
Bulbous octopus “head” is actually its mantle. The Head is small and
just around the eyes.
Mollusca
Characteristics:
-motility
-eyes
-Intelligent, in their own way
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Camouflage video
Chromatophores video
Octopuses are smart and squishy
Octopus sneaks back to sea
Dumbo octopus: really cute
Vampire squid: weird
Squid Anatomy (male)
squid dissection
colossal squid dissection interactive