Phylum Chordata
(Sea Otters and Polar Bears)
Kellsie M. & Rachel R.
Taxonomic Classification
Enhydra lutis
Domain – Eukarya
Kingdom – Anamalia
Phylum – Chordata
Class – Mammalia
Order – Carnivora
Family –Ursidae (Bear) & Mustelidae (Sea
Otter)
Genus – Enhydra (Sea Otter) & Ursus
(Polar Bear)
Species – lutis (Sea Otter) & maritimes
(Polar Bear)
Ursus maritimus
Key Characteristics
Polar Bears
•Their fur is thicker than other bears and it covers their
feet for warmth and traction on the ice
•Thick layer of blubber beneath fur provides buoyancy
and insulation
•They have a long neck and narrow skull which helps aid
streamlining in the water and their front feet are large,
flat, and oar- like
•They have canines and eat meat
Sea Otters
•They have long, slim bodies with short limbs that have
webbed paws
•Sharp claws on all feet
•Thick fur to keep warm because they have no blubber
•Hind feet are long, flattened, and fully webbed- helps with
swimming
•They have a muscular tail
Adaptations/Physiology
•
•
•
•
•
Sea Otters
Use their feet to reduce or maximize heat loss when water
temps are too hot or cold
When water temps are too cold they reduce heat loss by
floating on their backs with their feet out of the water
They control their lung capacity to increase buoyancy in cold
water and reduce lung volume to decrease buoyancy in
warmer water
Their nostrils and ears can close
Also, their feet and tails are adaptations
Polar Bears
• A polar bear's front paws propel them through the water
dog-paddle style. The hind feet and legs are held flat and
are used as rudders.
• A thick layer of blubber (fat), up to 11 cm thick, keeps the
polar bear warm while swimming in cold water.
• A polar bear's nostrils close when under water
• Body temperature, which is normally 98.6°F, is maintained
through a thick layer of fur, a tough hide, and an insulating
fat layer . This insulation keeps a polar bear warm even
when air temperatures drop to -34°F.
• Polar bears are so well insulated they tend to overheat
Habitat
Sea Otters
•
•
•
•
•
Live in the Pacific Ocean
Range from Soviet Union to California
Generally live in fairly shallow waters, the deepest waters being
40m
habitat is composed of the sea floor where they catch food and the
sea surface where they eat, groom, rest and socialize
Sea otters will frequently live in areas which have kelp beds
Polar Bear
•
•
•
Polar bears are found throughout the circumpolar Arctic
along or near coasts, on islands and on sea ice.
The polar bears live in areas where sea ice meets water to
hunt seals that make up majority of its diet
Some polar bears retreat each summer to the ice further
north that remains frozen year-round.
Reproduction
Sea Otters
•
•
•
Most don't successfully reproduce until they are five to seven
years old.
Female sea otters become mature at about four years. Males are
capable of mating at age five or six, but usually don't become
active breeders for several more years.
Sea otters breed throughout the year. Males may breed with more
than one female during the year.
Polar Bears
•
•
Males seek out females by following their scent. Two
males may fight over a female.
Females begin to mate around the ages of 4 or 5.
Males take longer to mature and usually begin
attempts to mate around the age of 5 or 6, though
their prime breeding years begin around age 10
FUN FACTS!
Polar Bears
•
•
•
•
Female polar bears would rather build their dens in "old snow"
from previous years rather than the freshly fallen snow.
Polar bear cubs learn to freeze and remain still while their
mother hunts. If they move, the mother disciples them with a
whack to the head.
Paw pads with rough surfaces help prevent polar bears from
slipping up on the ice.
A polar bear's fur is not white! It is hollow. The fur reflects light.
The hollow fur also traps the suns heat to help keep the polar
bear warm.
Sea Otters
•
•
•
•
•
Otters live on every continent except Antarctica and
Australia.
The sea otter’s fur is the finest and densest of any animal
fur.
The sea otter is the smallest marine mammal.
Sea otters are the only tool using mammal.
An otter’s coat has pockets, flaps of skin under their front
legs. Otter use them to hold their captured food until they
return to the surface
Sources
Book
Wikipedia
http://bioweb.uwlax.edu
http://www.seaworld.org/animal-info/info-books/polarbear/adaptations.htm
• http://www.bio.davidson.edu/Courses/anphys/2000/Boehm/Habitats.html
•
•
•
•