Bivalvia

Question 1

Which mollusc trend do Bivalves belong?

Answer 1

Diasoma
- two valves
- loss of head
- loss of radula

Question 2

Characteristics of Rostroconchs.

Answer 2

a. valves not independent
b. quasi-infaunal deposit feeders

Question 3

Characteristics of Bivalves.

Answer 3

a. head and radula lost
b. gills are respiratory organs and sometimes feeding
c. only have adductor muscles

Question 4

What are the 3 types of dentitions?

Answer 4

1. Taxodont
2. Heterodont
3. Edentulous

Question 5

Ligament types

Answer 5

1. Resilium
2. paravincular
3. duplivincular

Question 6

What do the different muscle structures inform?

Answer 6

Two muscles indicate the presence of a foot.
One muscle usually means no foot.

Question 7

Characteristics of Pteriomorphia and an example.

Answer 7

1. no or reduced foot.
2. iso or monomyarian musculature
3. Asymmetric
4. epifaunal suspension feeders.
5. Taxodont and duplivincular
   example - Oysters and scallops

Question 8

Characteristics of Isofilibranchia and an example.

Answer 8

1. Foot reduced
2. edentulous
3. anisomyarian
4. terminal jumbo
5. epifaunal suspension feeders
   ex. - Mussels

Question 9

Characteristics of Heteroconchia and an example.

Answer 9

1. foot present - isomyarian
2. Often have pallial sinus
3. siphons
4. heterodont
5. paravincular or residuum
6. infaunal suspension feeders.
   ex - clams and cockles