Term
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Definition
-
about 120 species
-
wormlike marine organs
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Term
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Definition
- about 250 speices
- no radula
- no gills bottom dwellers
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Term
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Definition
- begin in the paleozonic era
- long thought to be extinct
- lives on ocean floor
- rounded shell
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Term
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Definition
- about 1000 species known
- chitons
- bear 7 or 8 limy plates on dorsal side
- usually found in rocky parts
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Term
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Definition
- about 900 living species
- tusk shells
- benthic marine species
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Term
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Definition
- largest group with about 7,000 living species
- snails limpets slugs whelks conchs periwinkles sea hares
- usually sluggish snail like
- development in larva, the mouth is anterior to anus but during development the relative positions change
- coiling or spiral winding of shell happens
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Term
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Definition
-
the "hachet footed" animals
-
mussles clams scallops
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they have 2 shells "bivalvia"
-
many are sedentary filter feeder
-
lack radula & show little cephalization (concentration of nervous system and sense organs in head region)
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Term
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Definition
- the head foot molluscs
- molluscs squid octopi devil fish
- modified foot concetrated in head region; anterior margin of foot forms arms or tentacles
- all marine
- shell made light by a series of gas chambers
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