Great White Shark YRC9P0

Great White Shark

https://www.youtube.com/watch?v=zZVbSYRC9P0

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

Marine Mammals

Cetaceans Pinnipeds

Sirenians Polar bear

Sea otter

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

Problem and Solutions

Problem:

•Heat conductivity of water 25x that of air

Solutions?

Solutions

Insulation

Marine mammals - two forms of insulation

•Fur •Blubber

INSULATION THICKNESS (mm)

10 30 50 70 90 1100

0.5

1.0

1.5IN

SU

LA

TIO

N (

W-1M

2oC

)Still Air Dry Fur

Wood

Adipose

MuscleWater

Copper

Sea otter hair, Wet

Harbor porpoise blubber

Spotted dolphin blubber

INSULATION THICKNESS (mm)

10 30 50 70 90 1100

0.5

1.0

1.5IN

SU

LA

TIO

N (

W-1M

2oC

Still Air Dry Fur

Wood

Adipose

MuscleWater

Copper

Polar bear hair, Dry

Polar bear hair, Wet

Thermal Windows

•Feet

•Flippers•Dorsal fin

•Pectoral flippers

•Tailflukes

Rommel et al., ‘98

Countercurrent exchanger

Conclusions

Marine mammal solutions

•Insulation - fur and blubber

•Vasculature

Thermal Problem for Male Reproductive Systems

Problem:

• Sperm production requires lower temp

Terrestrial mammal solution

• Scrotum or cremaster sacs

Rommel et al., ‘98

The Cetacean Solution

Rommel et al., ‘92

Rommel et al., ‘98

12

34

5

Distance from Anus (cm)

Tem

pera

ture

(o C

)

37

36

35

IT WORKS!

Conclusions

Marine mammal solutions

•Decreased surface area

•Insulation - fur and blubber

•Vasculature

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