Oxygen Consumption in Fish Flashcards
the body temperature of ectotherms ____ with fluctuations in the external environment
varies
Endotherms utilize the heat produced from ___
___ ___ to maintain a high and constant body temperature.
Endotherms utilize the heat produced from internal
chemical reactions to maintain a high and constant body temperature.
The body temperature of aquatic ectotherms is largely determined by ____ and _____
equilibrium with the surrounding water
The body temperature of aquatic ectotherms is largely determined by conductive and convective
equilibrium with the surrounding water
what is heat conduction
Heat conduction (or thermal conduction) is the movement of heat from one solid to another one that has different temperature when they are TOUCHING each other.
what is heat convection
When a fluid, such as air or a liquid, is heated and then travels away from the source, it carries the thermal energy along. This type of heat transfer is called convection. The fluid above a hot surface expands, becomes less dense, and rises.
What happens to the metabolic rate of an ectotherm when the temperature increases?
it increases.
ammonia is a by product of ___ ___ and ___ ___ metabolism
Ammonia is a by-product of amino acid and nucleic acid metabolism
Ammonium ions are
excreted across the gills in exhange for ____ ____. The amount of ammonium excreted can
give some indication of changes in metabolic rate.
Ammonium ions are
excreted across the gills in exhange for sodium ions. The amount of ammonium excreted can
give some indication of changes in metabolic rate.
How can ectotherms behaviorally modulate their temperature?
they can exert some control over their body temperature via behavior by selecting their THERMAL ENVIRONMENT.
NH4 excretion rate has an ____ relationship as environmental temperature increases
EXPONENTIAL
Specific MR (ml O2/hr/g) consumed by medaka at various temperatures exhibits a ___ relationship
linear.
Explain relationship between Ta and Tb for ectotherms and endotherms
for ectotherms: ta varies with tb
for endotherms: tb is independent from ambient temperature.
How does O2 solubility vary with increasing temperature?
O2 solubility DECREASES with increasing temperature.
why is more ammonia produced at higher temperatures?
because the fish/ectotherm is more active and is undergoing more nitrogenous metabolism (nucleic acid and amino acid), resulting in increased ammonia release in an exponential fashion.
Why can an ectotherm behaviorally act in a “faster” manner in hotter environments?
because their metabolism is faster! Faster aerobic reactions = more atp= more energy
enzyme kinetics are faster at higher temperatures. Reaction speeds up, channel opening speeds up, and allows for increased activity.
however, because the metabolism is faster, its kind of like a POSITIVE FEEDBACK LOOP and more O2 is required to fuel it.
Therefore, the higher the temperature, the faster the metabolism, the more and more O2 required.
