1. Order Cetacea & Sirenia Classification and Characteristics
Marine Mammals
Order Cetacea & Sirenia
Classification and Characteristics
Order Cetacea & Sirenia

2. Order Cetacea Mysticeti (Baleen whales) Odontoceti (Toothed whales)
Have made the most complete transition to aquatic life
Have considerable morphological and ecological variability, but all share similar characteristics
Convergent evolution – different spp. develop similar structures due to a similar lifestyle
Order Cetacea & Sirenia

3. Cetacea Characteristics
Elongated telescoped skull
Nostrils are on top of the head instead of in front, forming a single or double blowhole
Have a pair of front flippers, but the rear limbs have disappeared
Flukes are used for propulsion
Order Cetacea & Sirenia

4. Suborder Mysticeti Toothless or baleen whales, 11 spp.
Filter feeders which use baleen
Posses symmetrical dorsal skull with 2 blow holes
Are the largest whales and the largest animals that ever lived on earth
Order Cetacea & Sirenia

5. The Roqurals Includes: blue, fin, minke, and humpback
Feed by gulping large schools of krill or small fish
The lower part of the throat has grooves on the underside which distend when feeding
Blue Whale
Order Cetacea & Sirenia

6. The Right Whales Includes: Bowhead and right whales
Swim at the surface with their mouths open
Northern Right whale
Order Cetacea & Sirenia

7. Mysticeti Feeding Types
Order Cetacea & Sirenia

8. Suborder Odontoceti
Includes: Sperm whales, narwhals, beaked whales, oceanic dolphins, true porpoises, and river dolphins
Have teeth, adapted for a diet of squid, fish and other marine mammals
Dorsally asymmetrical skull with a single blow hole
More variable morphologically and ecologically
Order Cetacea & Sirenia

9. Sperm Whale Largest of the toothed Whales on earth (Physeter catodon)
Eat squid, especially from great depths
Squid beaks and other undigestibles accumulate in the gut creating ambergris
Order Cetacea & Sirenia

10. Killer Whale Orcinus orca is common in cold water, worldwide
Two distinct groups of killer whales
Piscivores
Marine mammal carnivores
Order Cetacea & Sirenia

11. Dolphins & Porpoises Dolphins Porpoises Falcate dorsal fin
Conical teeth
Distinct beak
Porpoises
Triangular dorsal fin
Spade shaped teeth
Lack a beak
Order Cetacea & Sirenia

12. Order Sirenia Inhabit shallow water and feed strictly on plants
Herbivores - digestive tract is similar to horses and elephants
Use a prehensile upper lip to feed
Occupy tropical and subtropical waters
Order Cetacea & Sirenia

13. Is it the Rum, or are you beautiful?
Have been exploited for their meat (tastes like veal) and oil- rich blubber
Reproduce slowly 1 calf ever 3 years
Only four species remain, all close to extinction
Dugongs – 10 ft. and 930 lb. (East Africa to some pacific islands)
Manatees – 15 ft and 1,320 lb.
Order Cetacea & Sirenia