What are some ways to measure the physiology of an organism?
stress response, osmoregulation, energy stores, locomotion, metabolic rate, growth and reproductive output
What are the two systems in which a stress response is activated in fish?
Hormonal and nervous system
Describe the hormonal pathway of a fish stress response.
hypothalamus-pituitary-inter-renal tissue-corticosteriod release
What are the effects of long term corticosteroid release?
continually release glycogen stores, and immunosuppression
What is the role of heat shock proteins in the stress response?
refold or degrade misfolded proteins
What is the nervous system response to stress?
hypothalamus-pituitary-chromaffin tissue-catecholamine release
What do catecholamines do?
mobilize energy reserves and increase heart rate
What is the difference between osmolarity and osmolality?
osmolarity: osmoles/volume
osmolality: mols of osmoles needed to maintain osmotic pressure
How does the ion regulation differ in freshwater to seawater fish?
ions are constantly leaving the freshwater fish so they need active uptake while the salt water fish are consistently bringing them in
What does euryhaline and stenohaline mean?
Euryhaline-tolerant to saltwater
Stenohaline-sensitive to changes in ion concentration in water
How can toxicants disrupt ion regulation?
Metals mimic ions and pass through in the gills
Why are energy stores needed?
heat, locomotion, metabolism and growth
What are the two measures of locomotion?
Ucrit and sprint speed
What is ucrit?
critical swimming speed-increase velocity of water in a swim tunnel and see when they give up
What is sprint speed?
body lengths per second, increase H20 velocity at much higher rates
What are RMR, AMR and ASA?
Resting metabolic rate, active metabolic rate and aerobic scope for activity
How do you determine the energy available to an organism?
AMR-RMR=ASA
How can metals impact metabolic rate?
the metals clog the gills, lower swim speed due to decreased metabolic rate, AMR and ASA decrease
What is a way to track metabolism in embryos and provide an example?
check heart rate-after oil spill there was a decrease in HR and irregular heart beat
What is the role of the thyroid?
regulation of energy use, protein production, and thyroid hormone production
What is the active form of the thyroid hormones?
T3
What is an example of a toxicant causing issues with metabolism?
Seals exposed to PCBs saw decreased levels of T4
What are the growth parameters?
specific growth rate, development time and size at age
How do you measure specific growth rate?
weigh the organism
