Whales and Dolphins

Cetaceans:

Cetaceans are marine mammals that are obligatorily aquatic. Typically divided into two groups: Odontoceti (Toothed whales) and Mysticeti (Baleen whales), cetaceans are extremely widespread and diverse. Dolphins like the Orca (largest member of the dolphin family) are found in all seven oceans (Nowak 2003). Similar to pinnipeds, cetaceans rely on blubber. Providing energy and regulating internal temperature, buoyancy, and streamline, blubber is extremely important (Nowak 2003). The internal skeleton of cetaceans is composed of oil filled porous bones. This allows long, deep dives while minimizing pressure damage to bones (Nowak 2003).

 

(www.turtletrack.org)

 

 

Differences Between Toothed and Baleen Whales

Toothed Whales: Orcas, Belugas
Baleen Whales: Minke, Humpback, Blue
Head Shape
Asymmetrical: Defined rostrum, melon and conical teeth
Symmetrical shape with large baleen plates
Vocalization
High pitched, short ranged frequencies
Low, long ranged frequencies
Socialization
Social: live in pods
Solitary: gather for breeding
Sexual Dimorphism
Males larger than Females
Females larger than males
Feeding
Predatory
Filter feeds
Social Structure
Patriarchal
Matriarchal
Blowholes
Single blowhole
Multiple blowholes (usually 2)

 

 

Anatomy

http://monyscurry.com/dolphins.htm

 

Orcas

(www.wildernesscommittee.org)

 

Page by: Lindsay France: Environmental Science; Interdisciplinary Arts and Sciences; University of Washington, Tacoma

Advisor: Dr. Bonnie J. Becker (For more information contact Dr. Becker at BJBecker at u dot washington dot edu)

Source: Nowak, R. M. 2003. Walker's Marine Mammals of the World. 6th ed. John Hopkins University Press. London.