Marine Mammal StudyResearch conducted by the Sonoma Science Museum

in conjunction with the Rightfield County Aquarium

Marine MammalsPrior education needed for understanding our research

An OverviewA marine mammal is a

mammal that is well adapted to living in a marine environment.

There are two major groups, each containing further separation:Cetaceans

Mysticeti Odontoceti

Pinnipeds Phocidae Otaridae Odobenidae

Comparing the GroupsCetaceans PinnipedsConsists of whales,

dolphins, and porpoisesCharacterized by

streamlined bodies that glide easily

Consists of seals, sea lions, and walruses

Characterized by large fin-like flippers

SSM Biological ResearchWhat we focused on

An OverviewThe Sonoma Science Museum teamed up with the

Rightfield County Aquarium to conduct a study on various marine mammals housed at the aquarium

Dr. Alexander Forry (SSM) and Sean Hamm (RCA) were heading the team of researchers

Much of the study focused on comparing the different orders and the species variations within them

Comparing CetaceansBeluga WhaleBottlenose Dolphin

Beluga Whale (Delphinapterus leucas)

Belugas are the only cetaceans that are able to move their head up, down, and side to side

They lack a dorsal fin and do not produce a visible “blow” when breathing at the surface

Bottlenose Dolphin (Tursiops truncatus)

They use high frequency echolocation to locate and capture prey

This species is very long-lived, with a lifespan of 40-45 years for males and more than 50 years for females

Comparing Physical Characteristics

One of the main ideas our researchers focused on were the physical differences between different species of cetaceans.

Here you will see the differences in length.

Comparing PinnipedsCalifornia Sea LionNorthern Fur Seal

California Sea Lion (Zalophus californianus)

Very social and form groups of several hundred when onshore

They are the most recognized pinniped because they are frequently found doing tricks in zoos and aquariums

Northern Fur Seal (Callorhinus ursinus)

They have the longest flippers in the Orariidae family; their hind flippers can measure up to 1/4 of the total body length

Northern fur seals have very dense coats, for which they are named

Comparing Physical Characteristics

This chart notes the differences in weight between the California Sea Lion and the Northern Fur Seal.