Download Phylum: Mollusca

Page 530
Phylum: Mollusca
Snail, oyster, squid,
octopus, slug, chiton
Characteristics
 Soft
body (yummy part!)
 Muscular system: Muscular foot
(movement)
 Visceral mass (contains organs)
 Most have a shell
 Produced by the mantle
 Have
a true body cavity (coelom)
 Reproductive System: Most
reproduce sexually
 Most have an open circulatory
system
 Not all blood moves in vessels
 Excretory System: Nephridia
Three Main Classes
1.
Gastropoda
--”stomach foot”
--snails, slugs, conchs
--Respiratory system: gills
--have a tongue with
teeth..radula
--Herbivore—eats plants
2. Bivalvia
 “two
shells”
 Clams, oysters, scallops,
mussels
 Filter feeders
 Found in fresh
and salt water
Page 533 Eyespots
3. Cephlapoda
 “head
foot”
 Octopus, squid, nautilus,
cuttlefish
 Highly developed nervous
system
 CLOSED circulatory system
 Predators
 Can
change color
 Squirt ink for protection
 Have eyes like us
 Tentacles with suction cups
 Squid = 10
 Octopus = 8
The Chambered Nautilus
 Chambered
shell
 Animal lives in outer chamber
 Other chambers are filled with
gas to control animal’s depth