Phylum Chordata Sea Otters and Polar Bears Kellsie

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 40 m 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