L20-physiology and change,gill oxygen limitation theory

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

controlled by area of surface and thickness of membrane

decreases as temperature increases

have most complex gills

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

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

• 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

metabolism required for animal to survive

metabolism required for both survival and for things such as growth

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

– 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

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

physics envy- search for universality very rare in biology

key factor with climate change is Aerobic scope

key factor with climate change is Gill area

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