Hyperosmoregulation Flashcards
1
Q
What are the 3 main challenges bony fish and lamprey face in freshwater
A
- diffusional salt loss across body surface
- osmotic water influx
- incidental water influx during feeding
2
Q
Where is most salt loss in bony fish and lamprey?
A
- gills, they’re designed for gas exchange
3
Q
What does osmotic water influx cause?
A
- swelling/water loading
4
Q
What are the 4 solutions to overcome freshwater challenges?
A
- do not drink
- highly impermeable skin
- produce copious dilute urine
- active ion uptake via gills
5
Q
What causes highly impermeable tegument?
A
- deep tight junctions minimize passive loss of ions
6
Q
What does the kidney act as in freshwater fish?
A
- bilge pump
