Gas Exchange in Bony Fish Flashcards
1
Q
What is the operculum?
A
The flap that covers the gills
2
Q
Why are fish always moving? What would happen if they stopped moving?
A
To ventilate their gills.
The flow of water would also stop and they would not have a flow of water and their blood would not receive the oxygen it needs.
3
Q
How do fish ventilate their gills? (8)
A
- Mouth opens and buccal cavity is lowered. Opercular valve is shut
- Higher volume in cavity. Low pressure
- Water moves into the buccal cavity
- Opercular cavity expands, lower pressure
- Water moves into the opercular cavity, over the gills
- Mouth closes and the operculum opens. Sides of the opercular cavity move inwards
- Increase pressure in opercular cavity. Water moves out of gills and out of opercular
- Floor of the buccal cavity goes up (maintaining water flow)
4
Q
How are gills adapted for gas exchange?
A
- Tips of adjacent filaments overlap (provide resistance against flow of water so it flows slower - more time for gas exchange)
- Water and blood movement is in opposite directions (provide steep concentration gradient)
