Mollusca: Bivalvia

Question 1

synapomorphies (4)

Answer 1

two-valved shell,

no radula,

large muscular food,

ctenidia

Question 2

body wall and support

Answer 2

Body wall: soft bodied with a two-valved shell, held together by adductor
muscles

Support: shell or calcareous cement

Question 3

locomotion and body cavity

Answer 3

Locomotion: uses food to burrow, while other can clap the shells; mussels

Body cavity: true coelom with a hemocoel

Question 4

feeding/ digestion (2) and circulation

Answer 4

Feeding: filter feeds using ctenidia

Digestion: simple digestive system with a stomach digestive glands, and
intestines;

can house symbiotic bacteria to digest

Circulation: open circulatory system with hemolymph

Question 5

excretion and gas exchange

Answer 5

Excretion: nephridia to filter waste

Gas exchange: ctenidia to extract oxygen

Question 6

nervous system (2)

Answer 6

simple nervous system with ganglia;

eyes on mantle

Question 7

reproduction (3) and development (2)

Answer 7

Reproduction: dioecious or hermaphroditic;

external fertilization in
marine, while freshwater use internal;

some are parasitic

Development: indirect development with trochophore larvae,

while
freshwater species have a glochidium parasitic larvae

Question 8

Habitat

Answer 8

Marine and freshwater, such as rocky shores, coral reefs, and even
deep sea

Question 9

fun fact

Answer 9

Bivalves can filter large amounts of water, improving water
quality