Connecting With Other Classrooms
To contribute to the discussions below send e-mail to: JN-Talk@Learner.org
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Teacher Connecting With Other Classrooms To contribute to the discussions below send e-mail to: JN-Talk@Learner.org
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The Humpback Whale
The humpback whale is probably the most common of the giant
baleen whales. It was also once the most endangered. The species
developed around 10 million years ago and because its ability to change,
it continued to grow.
Humpback whales are seen in coastal waters all over the world. In
the summer they feed on the polar regions. In the winter they breed in
the tropics, with the exception of those in the Arabian sea. These
whales appear to stay the whole year in the same place. There are
humpbacks in the north Atlantic, north Pacific, and some scattered
throughout the southern hemisphere.
For centuries the oceans have been used as universal dumping
grounds. It was thought that toxic-waste would be diluted and dropped in
the sea and never seen again. How wrong we were! First they are taken by
the plankton, which in turn are eaten by the small fish or shrimps.
these are engulfed in huge quantities by the giant whales. The whales
throughout their own lives have been storing substances in their blubber
and in their livers.
Baleen whales are some of the largest animals. Their large size
allows for protection from predators, and is an advantage in species
that compete for mates. On land, animals must support their weight. In
the aquatic environment water helps support an animals body weight
allowing for the potential for greater size. Large size allows whales to
take advantage of high food productivity and store that energy in the
form of blubber.
All baleen whales show some variation of a characteristic torpedo
shaped body shape. this body shape reduces drag and is energy efficient
for swimming.
Most baleen whales change skin color changes of black and gray.
Some species show some extent of countershading; the top surface is
darker than the bottom surface. This coloration typical of many marine
animals, provide camouflage. The results is that predators or prey do
not see a contrast between the countershaded animals and the
environment.
Each lobe of their tale is called a fluke. Flukes are flattened
pads of tough fibrous connective tissue, completely without bone or
muscle. Flukes are oriented horizontalally. Longitudinal muscles of the
back and caudal penducle move the flukes up and down. Humpback whales
also have a small dorsal fin located on a hump. The shape of the dorsal
fin varies among the humpback whales.
Baleen whales have two blowholes located on the top of their head.
Blowholes are coverd by muscular flaps. These flaps provide a water
tight seal. There is a "splash guard" in the front of the blowhole
region in some species. This prevent water from entering the blowholes
upon surfacing to breathe. Each blowhole leads to an air passage that
leads to baleen whale's trachea nad then to its lungs.
Baleen whales have a smooth skin surface with no oil galnds or
pores. Many species have several hairs located on the snout jaws and
chin.
By Margot Seidman
Mrs. Berger Class
K12robzj@hofstra.edu or jberger@dorsai.org
Joan Berger
Internet Educational Consultant * * * * * * * * * * * * * * * *
Roslyn Public Schools * "...for the world is hollow *
Roslyn, NY 11577 * and I have touched the sky!"*
FAX (516)826-0358 * * * * * * * * * * * * * * * * *
**Visit the East Hills School WEB SITE at http://www.dorsai.org/~jberger/
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