October 8, 2008 How do fish get oxygen to their peripheral parts? What other types of mechanisms do fish use for respiration? How do fish deal with anoxic conditions?

A. B.

Sacramento blackfish rainbow trout Higher pH Med. pH Lower pH Higher pH Med. pH Lower pH Species differ in magnitude of Bohr & Root effects. More active species have bigger shifts & higher P50s (Hb lower affinity for O2)

As temperature increases, O2 decreases.

Hemoglobin shifts right with increases in temperature.

Questions for review. 1.Why do fish need hemoglobin? What is P50? Why does Hb (hemoglobin) have a saturation curve? Why doesn’t it all just bind at a certain [O2]? 2. Define the Bohr effect and the Root effect. What is their role in respiration? Why is the pH lower (and acidity higher) at the tissues? 3.Which critical processes happen at the gills and which happen at the tissues? Draw the Hb saturation vs. PO2 curves for “loading” at the gills and “unloading” at the tissues. 4.What pattern do we see across fishes with respect to Bohr effects & oxygen affinity (P50)? How do they help unload O2? 5. What types of adaptations do fish have to deal with low O2 in the environment? 6. Why is high water temperature so stressful for fish? Name 2 reasons. 7. What is anoxia and how do fish deal with it? 8. How does hemoglobin help reveal vertebrate bloodlines? (book question)