Seals and Sea Lions



Pinnipeds are physically unique from other marine mammals. The presence of vibrissae, wiser-like sensory organs with dedicated nerve endings, muscle fibers, and blood supply, allow for effective foraging. Subcutaneous blubber supplies the animal with energy, while controlling buoyancy, streamline, and thermo regulation. Blood shunting restricts blood flow to vital organs thus limiting the amount of oxygen consumed and extending the length of a dive (Nowak 2003). Pinniped eyes are set in deep cushions of fat allowing minimizing the effects of pressure (Nowak 2003)


Differences Between Seals and Sea Lions

Seals: Harbor Seal
Sea Lions: Fur Seals Stellar Sea Lions.
Land Movement
Walks on all fours
Aquatic Movement
Propulsion from fore-flippers
Propulsion from hind flippers
Sexual Dimorphism
Raised sagital crest; males larger
Males can be larger
Grunt and Hiss
Social: lives in colonies
Solitary: lives in aggregates
Role of Hair
Thin hair used for streamline
Dense hair used for insulation
Ear Viability
External Ear Flaps
Internal ear
Dives forward
Submerges vertically

(Compiled from Nowak 2003)


Harbor Seals




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.