Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Reading Assignment: • Chapter 6--Hydromineral Balance end Thermoregulation: • Cold-blooded -poor descriptor • Poikilotherm (n); poikilothermic (adj) – variable body temperature – opposite = homeotherm • Ectotherm (n); ectothermic (adj) – temp. determined by environment – opposite = endotherm end Why are fishes ectothermic? Heat generated by metabolism gills body skin end Behavioral Thermoregulation • nearly all fishes • choose from available temperatures • concept of temperature preference end Temperature Preference: Preferred Temperature Frequency stenotherm eurytherm 0 20 Temperature C 40 end Temperature Preference continued: Preferred Temperature Frequency cold adapted warm adapted 0 20 Temperature C 40 end Temperature Preference continued: Preferred Temperature Frequency The effect of Acclimation 0 20 Temperature C 40 end Temperature Preference continued: The effect of Acclimation Preferred Temperature C final preferred temperature 40 bluegill temperature tolerance 20 0 0 20 40 Acclimation Temperature C end Temperature Preference continued: The effect of Acclimation Preferred Temperature C final preferred temperature 40 bluegill guppy ??? 20 chum salmon 0 0 20 40 Acclimation Temperature C end Physiological Thermoregulation • • • • few fishes--tunas & lamnid sharks fish are active --generate heat rete mirabile for heat exchange & conserv. fish are large--low surface area to mass ratio – body surf. area increases as square of length – body mass increases as cube of length end Physiological Thermoregulation gills skin rete mirabile body skin heat end Counter-current blood flow from body high Temperature heat low venous blood arterial blood from gills tuna typical fish Distance along capillaries (rete) end Counter Current flow: • fluid flowing in opposite directions • exchange of heat or gas perpendicular to flow • efficiency versus speed end Hypothetical Co-current blood flow: from body low venous blood counter-current heat Temperature high arterial blood from gills Distance along capillaries (rete) end Hypothetical Co-Current flow: • fluid flowing in same direction • exchange of heat or gas perpendicular to flow • speed versus efficiency • vessels naturally flow in opposite direction end end Hydromineral Balance: Life in a solvent Environmental forces cause movement of water and dissolved substances versus Homeostasis--the need to maintain balance of water and dissolved substances in cells and body fluids of organisms -constant internal environment end Environmental forces: • heat--(movement of molecules) energy for movement • diffusion--net movement of molecules • pressure--density of molecules – difference causes or blocks movement • osmosis--movement of water • electrochemical forces--attraction & repulsion of molecules based on charge end • Environmental forces work together toward equilibrium • equilibrium-no net movement of molecules end end Lecture Exam Monday • 100 point exam • covers lectures, assigned readings • 8-12 short answer questions; 4-6 pts ea – complete, concise answer – ex: definition • 3-5 longer questions; 10-15 pts ea • Finish by 1:55--budget time • Power Point lectures at: http://www.und.nodak.edu/instruct/skelsch/425~1.htm