AY Honors/Cetaceans/Answer Key

1. In what way is the Cetaceans family different to most other sea life?

Unlike most sea creatures, Cetaceans are warm blooded. They are all mammals too, which means they give birth to live young, nourish them with milk, and breathe air.

Another way to tell a cetacean from a fish is by the shape of the tail. The tail of a fish is vertical and moves from side to side when the fish swims. The tail of a cetacean – called a "fluke" – is horizontal and moves up and down.

2. Explain the difference between Baleen and Toothed Whales.

The baleen whales, also called whalebone whales or great whales, are one of two suborders of the Cetacea (whales, dolphins and porpoises). Baleen whales, rather than having teeth, have baleen plates which hang from the upper jaw and are used for filtering food from water. This distinguishes them from the toothed whales.

Baleen whales are generally larger than toothed whales, and females are larger than males. This group makes up the largest living animal species. Baleen whales have two blowholes, causing a V-shaped blow.

3. In what way have Whales and Dolphins been a benefit to man?

In some cultures, whales provide meat for both pets and for humans. Whales also provide oil for fuel, perfumes, and other products. Entire communities were established devoted to whaling. Although whaling is now illegal in most parts of the world, whales continue to provide benefits to man. They are a major tourist attraction in areas where they are common, and an entire industry has sprung up to bring people to see the whales.

There are many stories of dolphins protecting shipwrecked sailors against sharks by swimming circles around the swimmers. Because of their high capacity for learning, dolphins have been employed by humans for any number of purposes. Dolphins trained to perform in front of an audience have become a favorite attraction at many aquariums, for example SeaWorld. Such places may sometimes also provide an opportunity for humans to interact very closely with Dolphins. Dolphin/Human interaction is also employed in a curative sense at places where dolphins work with autistic or otherwise disabled children. The military has employed dolphins for various purposes from finding mines to rescuing lost or trapped persons.

4. Explain how it is that a Whale which breeds in the warm waters of the tropics can also survive the ice cold water of the Antarctica where they go to feed, (considering the whale is a warm blooded mammal like humans).

Whales have a very thick layer of fat beneath their skin called blubber. Blubber is a very effective insulator, much like a wet suit which is used for keeping divers warm when they swim in cold waters. Blubber is far more effective than a wet suit because it is so thick. In fact, blubber can comprise up to 50% of the body mass of some cetaceans during some points in their lives. Blubber also serves as a source of energy, and whales metabolize (burn) fat to generate heat internally and thus warm themselves. People metabolize fat too when they shiver (shiveing serves the same purpose - to warm us up).

5. Memorize the following Scriptures concerning whales:

• a. Genesis 1:21
• b. Ezekiel 32:2
• c. Job 7:12
• d. Matthew 12:40

7. Successfully draw a Baleen Whale and identify where the following body parts are:

a. Baleen Plates

These are the "strainers" in a baleen whale's mouth.

b. Blowhole

A cetacean breaths through this little hole in the top of its head.

c. Dorsal Fin

The fin on the top of many cetaceans.

d. Ear

These are hard to see because they're so small, but cetaceans all have them on the sides of their heads.

e. Eye

The better to see you with!

f. Throat Pleats

These are the folds in a baleen whale's throat and allow the whale's throat to expand when it fills its mouth with water to filter its food through its baleen.

g. Flukes

The tail.

h. Flippers

The fins on the side.

i. Genital Slit

The reproductive organ of a female cetacean.

j. Median Notch

The notch in the middle of the trailing edge of the fluke.

k. Peduncle

The part of the body that to which the fluke is attached.

Notes

This honor is very similar to Marine Mammals. Why not teach them both at the same time?