1. Great White Shark https://www.youtube.com/watch?v=zZVbS YRC9P0

2. https://www.youtube.com/watch? v=Pk-G8g3wXOg

3. Marine Mammals Cetaceans Pinnipeds Sirenians Polar bear Sea otter

4. What’s the big deal about being an aquatic mammal?

5. Problem and Solutions Problem: Heat conductivity of water 25x that of air Solutions?

6. Solutions  Insulation Marine mammals - two forms of insulation FurBlubber

7. INSULATION THICKNESS (mm) 10 30507090110 0 0.5 1.0 1.5 INSULATION (W -1 M 2o C) Still AirDry Fur Wood Adipose Muscle Water Copper Sea otter hair, Wet Harbor porpoise blubber Spotted dolphin blubber

8. INSULATION THICKNESS (mm) 10 30507090110 0 0.5 1.0 1.5 INSULATION (W -1 M 2o C Still AirDry Fur Wood Adipose Muscle Water Copper Polar bear hair, Dry Polar bear hair, Wet

9. Thermal Windows Feet Flippers Dorsal fin Pectoral flippers Tailflukes

10. Rommel et al., ‘98

11. Countercurrent exchanger

12. Conclusions Marine mammal solutions Insulation - fur and blubber Vasculature

13. Thermal Problem for Male Reproductive Systems Problem: Sperm production requires lower temp Terrestrial mammal solution Scrotum or cremaster sacs

14. Rommel et al., ‘98

15. The Cetacean Solution Rommel et al., ‘92

16. Rommel et al., ‘98

17. 1 2 3 4 5 Distance from Anus (cm) Temperature ( o C) 37 36 35 IT WORKS!

18. Conclusions Marine mammal solutions Decreased surface area Insulation - fur and blubber Vasculature

19. Structure without function is a corpse; function sans structure is a ghost - Vogel and Wainwright, ‘69