L20-physiology and change,gill oxygen limitation theory

Question 1

oxygen capacity limited thermal tolerance

Answer 1

calculated by minusing active oxygen consumtion-standard oxygen consumption to determine its limit
how efficient can take oxygen changes with temperature.
not all species support pattern

Question 2

diffusion across exchange surface

Answer 2

controlled by area of surface and thickness of membrane

Question 3

oxygen in water

Answer 3

decreases as temperature increases

Question 4

active and complex animals

Answer 4

have most complex gills

Question 5

gill oxygen limitation theory

Answer 5

gill surface is an area
tissue is a volume
tissue demands can increase faster than gills can cope with SA to volume ratio
dimensional tension constraints growth
should be pretty universal

Question 6

gill oxygen limitation theory predictions

Answer 6

things grow faster if smaller
relative gill area is high for small animals and low for big animals
as temperature changes oxygen use increases exponentially
so with increasing temps animals have a smaller maintenance metabolism meaning have to be smaller

Question 7

Gill Oxygen Limitation Theory atlantic cod

Answer 7

• Scaling of oxygen availability (gill area)
• The effect of temperature on oxygen demand
• Water-breathing ectotherms are predicted to get
smaller as the climate warms
cod seen smaller as temp gets warmer

Question 8

maintenance metabolism

Answer 8

metabolism required for animal to survive

Question 9

living metabolism

Answer 9

metabolism required for both survival and for things such as growth

Question 10

Gill Oxygen Limitation Theory ratio of gill area to metabolic rate?

Answer 10

The ratio of gill area to metabolic rate doesn’t
change with size

Question 11

The ratio of gill area to metabolic rate doesn’t
change with size
can be interpreted in different ways

Answer 11

– Gill area constraints metabolism and growth because
the geometry of gills limits metabolism to using only the
amount of oxygen that the gills can supply
– Gill area doesn’t constrain metabolism and growth,
because gills have evolved to match the metabolic
(and oxygen) requirements of the organism

Question 12

Do fish have the ability to simply grow larger gills?

Answer 12

fish can change the shape of gills to make them larger as temperature increases.
if temp goes up or experience hypoxia they cover less of gill making it effectively larger
observed in goldfish and carp
very efficient for ion exchange

Question 13

Problem in biology?

Answer 13

physics envy- search for universality very rare in biology

Question 14

Oxygen- and capacity-limited thermal
tolerance

Answer 14

key factor with climate change is Aerobic scope

Question 15

Gill oxygen limitation

Answer 15

key factor with climate change is Gill area

Question 16

How would you expect an animal to
respond to climate change?

Answer 16

– Is your expectation influenced by:
• Thermoregulation (endotherm or ectotherm)
• Where they live (terrestrial or aquatic)
• How they forage (vision important or not)