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.

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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

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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.

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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.