Ectotherms lecture 3

Question 1

What is the difference between breathing in water and air?

Answer 1

Water has a lower O2 compared to air
It is also harder to move volumes to sift out the oxygen
This means that more energy is expended by aquatic animals when breathing

Question 2

What is the difference in oxygen content of water when comparing both different temperatures and salt water vs fresh water?

Answer 2

As the temperature decreases the level of oxygen increases

Freshwater has a higher level of oxygen content than saltwater

Question 3

What is the effect of the different solubility of gases?

Answer 3

CO2 is more soluble than O2 leading to ocean acidification

Question 4

What are the key components of a fish gill?

Answer 4

Gill filaments
Gill arch
Gill rakers

Question 5

What is the difference between ventilation in sharks and bony fish?

Answer 5

In order for gaseous exchange to occur water must constantly be flushed over the gill filaments
Sharks achieve this by ram ventilation which requires them to continually swim while bony fish use a buccal pump where the operculum can be used to flush water over the gills so the fish does not need to constantly swim

Question 6

What is counter current flow and how is it useful in fish respiratory systems?

Answer 6

The blood flows in an opposite direction to water flow this results in a constant concentration gradient driving oxygen movement from the water to the fish making respiration more efficient

Question 7

What is unique about the icefish respiration system?

Answer 7

This fish has its metabolism at -1.87 degrees celcius with high ventilation flow of water with high O2, the fish also has high cardiac output, low blood viscosity
It is unique as it does not use a hemaglobin type molecule to transport oxygen to the tissues

Question 8

What is the Bohr effect?

Answer 8

Hemoglobin retains less O2 at lower pH (higher CO2)