Chapter 16: Phylum Mollusca, Class- Bivalvia Flashcards
1
Q
This classes includes what four organisms?
A
- mussels, clams, oysters and scallops
2
Q
They are ___ compressed and two parts of ___ are held together by a ligament.
A
- laterally
- shell (valves)
3
Q
The valves are drawn together by what muscles?
A
- adductor
4
Q
What is the oldest part of the shell?
A
Umbo
5
Q
How do you figure out the left and right sides of the shell?
A
- identify the Umbo
- hold it up with the Umbo facing you and have it orientated so the shell is upright with the side closest to the Umbo. (posterior end)
- Now it matches you
L>your right is its right etc
6
Q
Explain the purpose and process of pearl production?
A
- protective device used when foreign objects become lodged between the shell and mantle (nacre)
- secretes many layers of nacre around the object
- certain species of oysters are used
7
Q
- Most are ___ feeders.
- Respiratory currents bring both ___ and ___ materials to the gills.
- Muscous masses slide down the outside of the gill towards __ grooves.
A
- filter
- oxygen, organic
- food
8
Q
Some burrow into ___ (shipworms) and have bacteria which help them do what?
A
- wood
- digest cellulose
9
Q
- The sexes are usually ___.
- Gametes discharged to be carried out with the ___ flow.
- Fertilization is usually __.
- Embryo develops into ____, ___ and ___ stages.
A
- separate
- excurrent
- external
- trochophore, veliger and spat
10
Q
- Most fresh water clam’s fertilization occurs where?
- Eggs drop into __ where they are fertilized by sperm entering __.
- Develop there into a ___ larva stage.
- Attach to __ or __ of fish and live as parasites for several weeks.
- This is an adaptation for what?
A
- internally
- gills, gills
- glocidium
- gills or skin
- distribution
11
Q
What is an extremely invasive species of bivalves?
A
- zebra mussels
- high reproduction rates
- from Europe
- crazy filter feeders
L> stealing resources from other species
