1. Reading Assignment: Chapter 6--Hydromineral Balance end

2. 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

3. Why are fishes ectothermic? Heat generated by metabolism skin body gills end

4. Behavioral Thermoregulation nearly all fishes choose from available temperatures concept of temperature preference end

5. Temperature Preference: Temperature C 0 4020 Frequency Preferred Temperature eurytherm stenotherm end

6. Temperature Preference continued: Temperature C 0 4020 Frequency Preferred Temperature cold adapted warm adapted end

7. Temperature C 0 4020 Frequency Preferred Temperature Temperature Preference continued: The effect of Acclimation end

8. 0 4020 Acclimation Temperature C Preferred Temperature C Temperature Preference continued: The effect of Acclimation 20 0 40 final preferred temperature bluegill temperature tolerance end

9. 0 4020 Acclimation Temperature C Preferred Temperature C Temperature Preference continued: The effect of Acclimation 20 0 40 final preferred temperature chum salmon bluegill guppy ??? end

10. 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

11. Physiological Thermoregulation body skin gills heat rete mirabile end

12. Counter-current blood flow Distance along capillaries (rete) Temperature low high arterial blood venous blood heat from gills from body end typical fish tuna

13. Counter Current flow: fluid flowing in opposite directions exchange of heat or gas perpendicular to flow efficiency versus speed end

14. Distance along capillaries (rete) Temperature low high Hypothetical Co-current blood flow: from gills from body arterial blood venous blood counter-current heat end

15. 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

17. 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

18. 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

19. Environmental forces work together toward equilibrium equilibrium-no net movement of molecules end

21. 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