Hobbies And Interests
The Blue Whale
The blue whale is the largest animal alive in the 21st century. It can grow between 72 and 100 feet long, and the females are larger than the male. The blue whale makes low frequency sounds that travel thousands of miles in deep water. The sounds are inaudible to humans. The blue whale is solitary or travels in small groups in seas all over the world. It feeds almost exclusively on krill, a shrimp-like crustacean. The blue whale passively eats by sucking in huge amounts of krill-filled water and then straining out the water while catching the krill on its baleen, or horny filtering plates in its mouth.
The Walrus
The walrus is an enormous seal. The male can be from 9 to 12 feet long and weigh 1,640 to 3,400 lbs. while the female can be from 7 to 10 feet long and weigh 1,250 to 2,300 lbs. Both male and female walruses have tusks, whiskers and blubbery wrinkled skin that's warm pinkish brown when it's out of water and pale blue gray when it's in the water. Unlike the whale, the walrus can leave the ocean, but it moves slowly on land using its flippers. It dives to the floor of the sea to hunt for mollusks. Walruses are gregarious and often form colonies of thousands of animals. The tusks are used mainly for display, for fighting between males, to help the animal haul itself out of the sea or for cutting through the ice to make breathing holes. Walruses live on moving ice packs on the waters of the continental shelf on the Atlantic or Pacific oceans or on rocky coastal beaches.
Flippers
Both whales and walruses descend from terrestrial animals. The whale descended from an omnivore very much like a wolf or a hyena, while the walrus descended from a creature like a weasel. When they returned to the sea, the limbs of both evolved into flippers to better help them swim. The back limbs of the whale disappeared entirely save some vestigial bones. The name Pinnipedia, the suborder to which the walrus belongs, means fin foot. X-rays of both the whale and walrus' flippers show a structure very much like a hand.
Breathing Air
Both animals breathe air, despite their aquatic lifestyle. Because the blue whale never leaves the water, its nostrils are now on the top of its head and it must come to the surface to breathe. It breathes about 20 times in 20 second intervals before it dives again. On the last breath, the tail flukes might appear above the water. The walrus, if it doesn't haul itself out of the water altogether, simply sticks its head above the water to breathe since its nostrils are located in the same place as most other mammals.