1. Let’s Begin by Examining Respiratory Structures in Selected Aquatic Animals Focus on structure and function Focus on the diffusion rates and solubility characteristics of oxygen and carbon dioxide Focus on supplemental means for acquiring sufficient oxygen

2. Respiration in Unicellular and Small MultiCellular Organisms

3. Annelid Respiration

4. Bivalve Mollusc

5. Crab Gill = blood flow = water flow lamellae afferent vessel efferent vessel branchial chamber

6. Fish Gill

8. 0 50 100 10 20 30 40 90 80 70 60 Concurrent Exchange 0 90 10 100 7080 5060 3040 1020 Countercurrent Exchange

9. P O2 Length Countercurrent Exchange P O2 Length Concurrent Exchange

12. Ram ventilation - swimming with open mouth Obligatory - e.g. some sharks and tuna Facultative - e.g. mackerel - switch to ram ventilation at swimming speeds >0.5 - 1 ms -1

13. Terrestrial Respiratory Structures Lungs Mollusca Crustacea Amphibia Reptilia Aves Mammalia Tracheae Insecta (no circulatory fluid involved - tubules branch and deliver air directly to tissues)

14. Insect Respiration

15. Open Spiracle in Grasshopper Closed Spiracle in Grasshopper

16. Insect Tracheal System

18. Lungs diffusion lungs e.g. pulmonate snails ventilation lungs e.g. vertebrates positive press. lungs e.g. amphibians suction lungs (subatmospheric press.) e.g. mammals

19. Amphibian (Frog) Lung

21. Avian Lung

23. Respiratory Tract

24. Alveoli

25. pleural cavity lung diaphragm trachea bronchus Mammalian Lung

27. diaphragm exterior intercostals Inspiration == -- air

28. Expiration elastic recoil (surface tension) Internal intercostals air