Mollusca

Question 1

Phylum Mollusca

Classes (4)

Answer 1

Polyplacophora (chitons)
Bivalvia (clams, mussels, oysters)
Gastropoda (snails and slugs)
Cephalopoda (octopus, squid, cuttlefish)

Question 2

Mollusca Characteristics

Answer 2

tripoblastic, bilateral symmetry
eucelomate (have coelom)
cephalization (little in bivalve b/c umbo)

Question 3

Mollusca body

Answer 3

complete digestive tract, open circulatory system (closed in cephalopods), muscular foot, dorsal visceral mass, mantle, radula (not bivalve)

Question 4

Bivalva Characteristics

Answer 4

No cephalization or radula

filter feeders, umbo (anterior), ventral foot, suspension feeders

Question 5

Cephalopod Characteristics

Answer 5

ventral foot is now arms and tentacles, radula is now buccal bulb, ink sacs, chromatophores (camouflage), funnel=siphon (jet propulsion), stellate ganglia

Question 6

Cephalopod shell modifications

Answer 6

Squid- pen
Octopus- none
Nautilus- shell
cuttlefish- cuttlebone

Question 7

Gastropod Characteristics

Answer 7

Trochopore and veliger larval stages, univalve coiled shell in most, torsion

Question 8

What Gasropod life stage is planktonic?

Answer 8

Trochopore

Question 9

Glochidium

Answer 9

parasitic larval stage in freshwater bivalves

-like pacman

Question 10

shell apex

Answer 10

umbo

Question 11

columella

Answer 11

supports the shell worls/coils

Question 12

operculum

Answer 12

hardend plate on the foot that plugs up the aperature

Question 13

banana slug

Answer 13

slime attracts water for gliding

• goblet cells produce placets to absorb water and prevent dessication
• chemicals in slime attract mates

Question 14

Sponge vs. Bivalve feeding

Answer 14

“gill” surfaces trap food particles and they get pulled by cilia and labial palps pull into mouth (like flagella and collar cells in sponge)

Question 15

bivalve fun fact

Answer 15

susceptible to water pollution, sensitive indicators of aquatic health