Common Name:
Blue Whale
Class: Mammalia
Order: Cetacea
Suborder: Mysticeti
Family: Balaenopteridae
Genus:
Balaenoptera
Species:
Balaenoptera musculus |
 |
Taxonomy/Description
Blue whales belong to
the Mammalian Order Cetacea, in the suborder Mysticeti. All baleen
whales belong to the suborder Mysticeti, which is Latin for
"mustached whales". The blue whale belongs to the rorqual family,
Balaenopteridae. The word "rorqual" means "tube whale or furrowed
whale", referring to the pleats on the lower jaws of rorquals. All
rorquals have baleen, a dorsal fin and throat grooves. Other
members of this family include the humpback whale, fin whale, and
minke whale. The blue whale's scientific name is Balaenoptera
musculus. Its generic name, Balaenoptera, means "winged
whale", which refers to the blue whale's dorsal fin. The blue
whale's specific name, musculus, means "little mouse". The
blue whale is currently the largest extant animal. Blue whales may
exceed 100ft in length and 100 tons in weight. Female blue whales
are usually larger than males of the same age. Blue whale's of the
northern hemisphere are smaller in size than those of the southern
hemisphere.

Habitat/Diet
Blue whales are found
in all oceans. Their major food sources, krill and euphausiids,
live in all regions. Temperate, tropical, and polar seas all supply
the blue whale with its invertebrate prey. The blue whale eats
about four tons of krill per day during the summer feeding season.
That's about 40 million krill each day! As the whale opens its
large mouth to gulp up the krill, the pleats of its lower jaw expand
to contain the large volume of water. The whale then presses its
tongue up against the roof of its mouth, straining the water through
its 520-800 baleen plates. These 20-40 inch plates are composed of
keratin, the same substance of fingernails and hair. The ends of
baleen are brush-like, preventing the krill from escaping. The
krill remain inside, and are consequently swallowed.

Behavior/Reproduction
Blue whales migrate
from cooler arctic waters to warmer temperate and tropical waters to
calve and feed. Calves are born at intervals of 2-3 years.
Gestation is about 12 months. A single calf is born weighing three
tons, with a length of 23-27 feet. A blue whale calf drinks 100
gallons of milk daily. From the fat rich milk it gains 200lbs and
1.5 inches in length each day. The calf will nurse for 7-8 months,
weaning when it reaches 52 feet. Blues reach sexual maturity at
6-10 years. Occasionally seen solitarily or in small pods, blue
whales are usually observed in pairs. Loose groups of 50 or more
have also been sighted.

Conservation
Blue whales are so
large that primitive whalers were unable to hunt them. The paddle
driven boats and hand harpoons were too small to bring down the
enormous blue whale. The use of steam powered boats, new whale
inflation techniques, and the invention of the exploding harpoon gun
by Norwegian whalers ended this animal's invulnerability. One blue
whale could yield 120 barrels of oil. What was once a population of
350,000 individuals shrank by 95%. The blue whale became so scarce
that whalers began to hunt other cetacean species. Only recently,
under international protection, has the current blue whale
population of 3,000-4,000 showed signs of recovery.
Photos courtesy Patty Geary, copyright
© 2003, all
rights reserved.