Males -1.4 to 2.0 m

Females -1.2 to 1.7 m.

Range from light gray to silver with dark spots.

Some are black or dark gray to brown with white rings.

Spots or rings are numerous on the dorsal surface and more sparse on the ventral surface

Limbs are adapted into flippers.

Foreflippers have all major skeletal elements of the forelimbs of land mammals

Flippers are short and webbed. Each has five digits of equal length.

The foreflippers have noticeable claws. The claws are blunt and measure about 2.5 to 5 cm. Use their claws for scratching, grooming, and defense.

Not as broad as hind flippers and have less resistance to water flow

Covered with hair

Five bony digits in the hind, or pelvic limbs

The first and fifth digits are long and stout; middle digits are shorter and thinner

Digits are webbed. When the seal spreads its flippers they look like a wide fan

Move flippers side to side to propel themselves in water. The flippers also function as a rudder.

A seal cannot rotate its hind flippers.

Moves slowly and caterpillar-like.

Covered with hair

Harbor seals have rounded heads with a fairly blunt snout

Lack external ear flaps

They have 34 to 36 teeth. The front teeth are pointed and sharp for tearing their food.

Vibrissae or whiskers grow from the thick pads of a seal's upper lip. They continually grow throughout a seal's life.

A harbor seal has a short, flattened tail between its hind flippers.

Harbor seals have thick, short hair. The coat has coarse guard hairs and finer but denser underhairs.

Denisty of the hair increases with age

Glands in the skin secrete oil which helps waterproof the hair

The hair does not provide any insulation

They molt each year after the breeding season, generally lasts one to two months

Not sexually dimorphic

No significant differences between females and males