The Blue whale is the largest creature of the sea, in fact, it is the
largest creature known to man. Contrary to what most people think, even though
Blue whales live in the sea, they are mammals. They breathe air, have their
babies born alive and can live anywhere from 30 to 70 years. The Blue whale is
a baleen whale, and instead of having teeth, Blue whales have around 300-400
baleen plates in their mouths. They fall under the category of the rorquals,
which are the largest of the baleen family. The scientific name of the Blue
whale is, Balsenoptera musculus.
Introduction Whales are separated into two groups, the baleen and
the toothed whales. The blue whale is the largest baleen whale and the largest
animal that ever lived on Earth, including the largest dinosaurs. Baleen are
rows of coarse, bristle-like fibers used to strain plankton from the water.
Baleen is made of keratin, the same material as our fingernails. They live in
pods, the have two blowholes. The blue whale has a 2-14 inch (5-30cm) thick
layer of blubber. Blue whales (Balaenoptera musculus) are baleen whales
(Suborder Mysticeti). They are one of 76 species and are marine mammals.
Background The Blue whale is called a ^rorqual^, a Norwegian word
for ^furrow^ referring to the pleated grooves running from its chin to its
naval. The pleated throat grooves allow the Blue whale^s throat to expand
during the huge intake of water during filter feeding; they can ^hold 1,000
tons or more of food and water when fully expanded^ (Small 1971). Blue whales
have 50-70 throat grooves.
Blue whales grow up to about 80 feet (25m) long on average, weighing about
120 tons. The females are generally larger than the males, this is the case
for all baleen whales. ^The largest specimen found was a female 94 feet (29m)
long weighing more than 174 tons^ (Satchell 1998). The head of the Blue whale
forms up to a quarter of the total body length. Compared with other rorquals,
the head is very broad. The blue whale heart is the size of a small car and
can pump almost 10 tons of blood throughout the body. They have a very small,
falcate (sickle-shaped) dorsal fin that is located near the fluke, or tail.
Blue whales have long, thin flippers 8 feet (2.4m) long and flukes that are
25feet (7.6m) wide.
The blue whale^s skin is usually blue-gray with white-gray spots. The
underbelly has brown, yellow, or gray specks. During the winter, in cold
waters, diatoms stick to the underbelly, giving it a yellow to silver- to
sulfur-colored sheen; giving the blue whale its nick-name of ^sulfur bottoms^.
Other names include Sibbald^s Rorqual and Great Northern Rorqual.
Blue whales (like all baleen whales) are seasonal feeders and carnivores
that filter feed tiny crustaceans (krill, copepods, etc), plankton, and small
fish from the water. Krill, or shrimp-like euphasiids are no longer than 3
inches. It is amazing that the world^s largest animals feed on the smallest
marine life. Blue whales are gulpers, filter feeders that alternatively swim
then gulp a mouthful of plankton or fish. ^An average-sized blue whale will
eat 2,000-9,000 pounds (900-4100kg) of plankton each day during the summer
feeding season in cold, arctic waters (120 days)^ (Hasley 1984).
The blue whale has twin blowholes with exceptionally large fleshy
splashguards to the front and sides. It has about 320 pairs of black baleen
plates with dark gray bristles in the blue whale^s jaws. These plates can be
35-39 inches (90cm-1m) long, 21 inches (53cm) wide, and weigh 200 pounds
(90kg). This is the largest of all the rorquals, but not the largest of all
the whales. The tongue weighs 4 tons.
Blue whales live individually or in very small pods (groups). They
frequently swim in pairs.
When the whale comes to the surface of the water, he takes a large breath
of air. Then he dives back into the water, going to a depth of 350 feet
(105m). Diving is also the way in which whales catch most of their food.
Whales can stay under water for up to two hours without coming to the surface
for more air. Blue whales breath air at the surface of the water through 2
blowholes located near the top of the head. ^ They breathe about 1-4 times per
minute at rest, and 5-12 times per minute after a deep dive^ (Hasley 1984).
Their blow is a single stream that rises 40-50 feet (12-15m) above the surface
of the water.
Blue whales are very fast swimmers; they normally swim 3-20 mph, but can go
up to 24-30mph in bursts when in danger. Feeding speeds are slower, usually
Blue whales emit very loud, highly structured, repetitive low-frequency
sounds that can travel form many miles underwater. They are probably the
loudest animals alive, louder than a jet engine. These songs may be used for
locating large masses of krill (tiny crustaceans taht they eat) and for
communicating with other blue whales.
Blue whales typically are found in the open ocean and live at the surface.
They are found in all the oceans of the world. The majority of Blue whales
live in the Southern Hemisphere. The subspecies found in the Southern
Hemisphere are the balaenoptera musculus. The smaller populations inhabit the
North Atlantic and North Pacific. These Northern Hemisphere Blue whales are
the balaenoptera brevicauda. They migrate long distances between low latitude
winter mating grounds and high latitude summer feeding grounds. They are often
seen in parts of California, Gulf of California (Sea of Cortez), Gulf of St.
Lawrence, Canada and the northern Indian Ocean. Blue whale breeding occurs
mostly in the winter to early spring while near the surface and in warm
waters. ^The gestation period is about 11-12 months and the calf is born tail
first (this is normal for cetaceans) and near the surface in warm, shallow
waters^ (Hasley 1984). The newborn instinctively swims to the surface within
10 seconds for its first breath; it is helped by its mother, using her
flippers. Within 30 minutes of its birth the baby whale can swim. The newborn
calf is about 25 feet (7.6m) long and weighs 6-8 tons. Twins are extremely
rare (about 1% of births); there is almost always one calf. The baby is
nurtured with its mother^s fat-laden milk (it is about 40-50% fat) and is
weaned in about 7-8 months. A calf may drink 50 gallons of mother^s milk and
gain up to 9 pounds an hour or 200 pounds a day. The mother and calf may stay
together for a year or longer, when the calf is about 45 feet (13m) long. Blue
whales reach maturity at 10-15 years.
Blue whales have a life expectancy of 35-40 years. However, there are many
factors that limit the life span of the Blue whale. Packs of killer whales (orcas)
have been known to attack and kill young blue whales or calves. Man also
hunted blue whales until the International Whaling Commission declared them to
be a protected species in 1966 because of a huge decrease in their population.
The Blue whale was too swift and powerful for the 19th century whalers to
hunt, but with the arrival of harpoon canons, they became a much sought after
species for their large amounts of blubber. They were also hunted years ago
for their baleen, which was used to make brushes and corsets. But it was their
size and high yield of oil that made them the target of choice for modern
commercial whalers. Before mans intervention there were 228,000 Blue whales
swimming the oceans of the world. ^Between 1904 and 1978, whalers scoured the
seas for this huge cetacean, most were taken in the Southern Hemisphere, many
illegally^ (Satchell 1998). As the population figure suggests, it was
relentlessly slaughtered for every reason imaginable, almost to the point of
Another reason why Blue whales are almost extinct is pollution. Mosst of
their illnesses are contracted by pollution.
It is estimated that there are about 10,000-14,000 blue whales world-wide.
Blue whales are an endangered species. They have been protected worldwide by
international law, since 1967. The blue whale was listed as endangered
throughout its range on June 2, 1970 under Section 7 of the Endangered Species
Conservation Act of 1969. They are not to be hunted by anyone for any reason
at all. Suggestions are that some populations may never recover.
Conclusion Although Blue whales are now protected, we still must not
hunt or kill them in their delicate balance of life. Some people believe that
whales and dolphins are animal of mystery and beauty, and that a dead whale is
an omen, good or bad. Most people say that all humans must protect all whales.
We need to save these great water giants.
Berger, C. 1998 Making Sense of the Songs Whales Sing. Natural Wild Life.
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Hasley, W. 1984. Collier^ï¿½s Encyclopedia. P.F. Coillier, Inc. New York,
Mulvaney, K. 1998. A Canny Way with Whalers. New Scientist. Volume 157,
Satchell, M. 1998. A Whale of a Protest: Animal-Rights Activists Hope to
Keep an Indian Tribe from Bringing Home the Blubber. US News and World Review.
Volume 125, Number 13.
Small, G. 1971. The Blue Whale. New York Columbia University Press. New
Zimmer, C. 1998. The Equation of a Whale. Discover. Volume 19, Number 4.