The Blue Whale
The blue whale, or Balaenoptera musculus is the largest creature
in the world. It is also the largest creature that has ever lived, larger
than any prehistoric animal. The largest accurately measured blue whale is
33.27 meters or 109 feet, 4 inches. They average about 160 tons, and may
grow up to 200 tons. The females average to be larger than the males,
and in the northern hemisphere, they are smaller in both length and
weight. A newborn calf is about 7 meters in length. They mature sexually
at the same time, about ten years of age. Females give birth to one calf
every two or three years. There is a twelve month gestation period. When
the calf is about 8 months old and 15 meters in length, they are weaned.
Their average growth during 'infancy' is about 85 to 90 kg a day.
The blue whale is a baleen whale, or mysticetes. Their main source of food is the plankton, an
animal that is a hundred million times smaller than the whale itself. By
swimming with their mouth open, their baleen simply filter out the tiny
shrimp and fish. One whale may consume up to 8 tons of plankton in
one day. Blue whales are found in the North Pacific, North Atlantic,
and the southern hemisphere around the Rio Grande do Sul in Brazil.
Prey to both man and killer whales, the numbers of blue whales
have seriously depleted. In the north, there are only about 1200
to 1700, a few hundred in the North Atlantic, and only 9000 in
the southern hemisphere remain, half of which are pygmy blue whales.
Andrea Vanessa & Erica @ the Advanced Technologies Academy