Among the animals that make their homes in the ­extreme polar regions of the planet, walruses are some of the most iconic. Their mustachioed faces and long tusks make them immediately identifiable, even though most people will never see one in the wild. ­Walruses live in the Arctic Circle alongside other denizens of the ice such as ­polar bears and narwhals.

• Most people don’t ­realize there are ­actually two subspecies of walruses. Atlantic walruses range from Canada to northern Europe, while Pacific walruses range from Alaska to northern Russia.

• Scuba divers would be most likely to see walruses on an Arctic dive expedition around Svalbard, Norway.

• Walruses are part of the pinniped clade, a scientific grouping that also ­includes seals and sea lions. ­However, walruses come from their own distinct family, Odobenidae, of which they are the only remaining living species.

• The ­females give birth after about 15 months, and they are known for ­doting on their children, cuddling them like ­human mothers and caring for them until they’re about 5 years old.

• A walrus’s most noticeable feature is its tusks, and that was the basis for the scientific name Odobenus rosmarus. The name is Latin for “tooth-walking seahorse,” and it comes from the walrus’s habit of using its tusks like a climber’s ice ax to haul itself onto ice sheets or cling to the edge while it floats in the water.

• Walruses can grow to an immense size — upwards of 10 feet long and weighing 2 tons — but they aren’t the biggest pinnipeds on the planet. That distinction goes to their cousins the elephant seals.

• Like elephant seals, walruses are highly social animals, often ­lounging on ice sheets in groups that can ­number into the hundreds.

• Also like elephant seals, male walruses get ­aggressive around mating time, using their large bodies and tusks to claim ­territory and harems of female walruses.

• On land, walruses are big, blubbery creatures, but they’re still fast. Unlike seals, which drag their bodies with their flippers, walruses can run on all fours.

• Of course, underwater is their true element. Walruses spend about two-thirds of their lives in the water, where they are as graceful as ballerinas.

• When it comes time to eat — which happens often for creatures this size — walruses go mostly for ­invertebrates such as sea cucumbers and clams. They find them on the seafloor by using their whiskers, which are as ­sensitive as ­human fingers.

• Walruses even have a special method for eating ­shellfish such as clams and mussels: They hold the shell in their mouth with their lips sealed around it, then create such strong suction with their tongue that the meat pops out of the shell.