11.6. Mirounga angustirostris: Elephant Seal http://www.ck12.org
11.6 Mirounga angustirostris: Elephant Seal
Common Name
- Elephant Seal
- Northern Elephant Seal
Description
The elephant seal is a humongous brown, marine mammal. This means that they live in the ocean. Other marine
mammals are dolphins, whales and other seals. The northern elephant seal is quite a bit smaller than its southern
relative. They range over the Pacific Coast of United States, Canada and Mexico. The seals are slaughtered because
of their blubber. They have oil-enriched blubber that hunters want. They were almost extinct. In 1892, there were
about 100 elephant seals left, and the only remaining colony was located in the Guadalupe Islands off the coast of
Baja California. Like all other marine mammals, the elephant seal is protected under the Marine Mammal Protection
Act.
Habitat
Elephant seals live from the Gulf of Alaska to Baja California on the coast where it is sandy and muddy. They
like the sand because it acts like a sunscreen. They rub it up on their body, and it protects them from getting a bad
sunburn in the hot sun. A popular breeding spot for elephant seals is the rocks of Race Rock, which is located on the
southern tip of the Vancouver Island in the Strait of Juan de Fuca. They are excellent divers. This helps in foraging
for food and avoiding their biggest predator, larger sharks.
Biology
Cell Biology
Like other plants and animals, the elephant seal has eukaryotic cells. Eukaryotic cells have a nucleus and many
organelles. The nucleus contains DNA (deoxyribonucleic acid - the genetic instructions that make each species
unique). Organelles are microscopic structures that make up a cell. Organelles include Golgi bodies, which transport
proteins either in or out of the cell. Cells also have cellular membranes and ribosomes. Ribosomes are responsible
for proteins in all living cells.
The elephant seal, and other mammals, has red blood cells. Red blood cells are in blood and help carry oxygen
to organs and other places in the body using a protein called haemoglobin. About 33% of the red blood cell is the
hemoglobin. Mature red blood cells in mammals lack a nucleus. (All of the other vertebrates have nucleated red
blood cells.)