1. Class Mammalia, Order Sirenia
Florida Manatee - Trichechus manatus latirostris

2. Bottom resting
Feeding
Swimming
Courtship A B C
Hartman, 1979

3. Manatees Strategies to stay on bottom at low cost
Dense and heavy bones
Dense skin
Large lungs
Ballast

4. Maneuverability Pectoral flippers or tailfluke
Contractions of hemidiaphragms
Position in water column
Pitch and roll

5. Compartmentalization
Need to be distinct muscular units
Separated by connective tissue elements
With separate sources of innervation
Termed “neuromuscular compartments”

6. Manatee hemidiaphragms are compartmentalized.
Hypothesis
Manatee hemidiaphragms are compartmentalized.

7. Rommel and Reynolds, 2000

8. Rommel and Reynolds, 2000

9. Methods
Gross anatomical studies

10. Manatee diaphragm
Rommel and Reynolds, 2000

11. Connective tissue elements
VC Bundles
Phrenic nerve

12. Connective tissue elements
VC Bundle

13. Connective tissue elements
VC Bundles X X X

14. Intrinsic Tongue Muscles
Multi-directional fibers
Intrinsic Tongue Muscles
Manatee Diaphragm
M. Newson, 1996

15. Branches of phrenic nerve
Innervation patterns
Phrenic nerve
VC bundle
Branches of phrenic nerve

16. Conclusions VC bundles separate diaphragm into 1.0 cm-wide blocks
Muscle fibers insert into VC bundles
Branches of phrenic nerve innervate groups of blocks
Compartments may be composed of groups of blocks

17. D. Perrine, 2001

18. CARIBBEAN

19. Class Mammalia, Order Sirenia
Caribbean (Antillean) manatee - Trichechus manatus manatus

23. Class Mammalia, Order Cetartiodactyla,
Class Mammalia, Order Cetartiodactyla, Suborder Odontoceti – toothed whales
Bottlenose dolphin (Tursiops truncatus)

24. By www. iucnredlist. org, CC BY-SA 3. 0, https://commons. wikimedia

25. Adults 6.6 to 13.1 feet 330 to 1,430 lbs. Males > Females
By Kurzon, CC BY-SA 3.0,

27. Class Mammalia, Order Cetartiodactyla,
Class Mammalia, Order Cetartiodactyla, Suborder Mysticeti – baleen whales
Humpback whale (Megaptera novaeangliae)