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Fish 475: Marine Mammalogy
Course website:http://faculty.washington.edu/glennvb/fish475
Pieter Folkens
Wednesday, 31 March 2010
Taxonomy
Cetaceans: General characteristics I:
1. Loss of rear limbs and pelvic girdle;2. Modification of front limbs as flippers;3. Propulsion by caudal spine;4. Development of caudal flukes lacking skeletal
elements.
1
2
3
4
Text reading reference: Section 1.2.2
Cetaceans: General characteristics I:
1. Loss of rear limbs and pelvic girdle;2. Modification of front limbs as flippers;3. Propulsion by caudal spine;4. Development of caudal flukes lacking skeletal
elements.
Cetaceans: General characteristics I:
1. Loss of rear limbs and pelvic girdle;2. Modification of front limbs as flippers;3. Propulsion by caudal spine;4. Development of caudal flukes lacking skeletal
elements.
Cetaceans: General characteristics I:
1. Loss of rear limbs and pelvic girdle;2. Modification of front limbs as flippers;3. Propulsion by caudal spine;4. Development of caudal flukes lacking skeletal
elements.
Cetaceans: General characteristics II:
5. Loss of pelage;6. Development of subcutaneous blubber layer;7. Development of dorsal nostrils.
Cetaceans: General characteristics II:
5. Loss of pelage;6. Development of subcutaneous blubber layer;7. Development of dorsal nostrils.
Cetaceans: General characteristics II:
5. Loss of pelage;6. Development of subcutaneous blubber layer;7. Development of dorsal nostrils.
Cetaceans: General characteristics II:
5. Loss of pelage;6. Development of subcutaneous blubber layer;7. Development of dorsal nostrils.
Cetaceans: General characteristics II:
5. Loss of pelage;6. Development of subcutaneous blubber layer;7. Development of dorsal nostrils.
Odontoceti: The toothed whales
• About 70-75 species;
• Diverse and (mostly) abundant in all the world’s oceans and seas;
• Concentrated in or near regions of high productivity;
• Typically do not make major migrations.
Text reading reference: Section 1.2.2.2
General characteristics of the Odontocetes I:
1. Skulls Asymmetrical (we’ll see this more clearly in lab);
2. Dorsal skull surface flat or concave;
3. Mandibles articulated distally (“mandibular symphysis” –important diagnostic feature in evolution and taxonomy);
4. Homodont dentition, with numbers of teeth highly variable – zero to many (“supernumerary”).
5. Modification of posterior mandible as an acoustic receptor
2
3
4
1
5
General characteristics of the Odontocetes II:
5. Nostrils single externally;5
General characteristics of the Odontocetes II:
5. Nostrils single externally;
6. Extreme development of acoustic transmission and sensory capabilities.
5
6
Odontocete families:
Ziphiidae: Beaked whales
Teeth few or absent, in some species present only in males;
Skull concave with sagittal crests
Grooved throat with expansion capability (unique among the odontocetes).
Cuvier’s beaked whale
Hubbs’ beaked whale
Odontocete families:
Monodontidae: Beluga and narwhal
Two species, occuring at present only in the high Arctic;
Most highly ice-adapted of all the odontocetes.
Odontocete families:Monodontidae: Beluga and
narwhal
Skulls flattened;
Belugas have moderate numbers of teeth;
Narwhals males have a tusk but no other teeth; females have no teeth.
Odontocete families:
Physeteridae: Sperm whale
Odontocete families:
Physeteridae: Sperm whale
One species, the largest of the odontocetes and one of the largest of all the whales;
Extreme development of diving and acoustic capabilities.
Strongly sexually dimorphic in size and ecology (males undergo extensive annual migrations as adults, females do not).
Odontocete families:
Physeteridae: Sperm whale
Teeth only in lower jaw;
Extreme asymmetry of skull;
Left nostril does not open to the exterior, functioning only in acoustic context; All respiration through the right nostril;
“Deflected” blow at sea.