Subject: Whale Questions

Martine Berube (martine@newt.bio.uci.edu)
Sat, 25 Oct 1997 17:01:40 -0700

Question4: How many different kinds of molecules do you find in whales' skin ?

Dear Lauren,

I am not an organic chemist but I can tell you that a single cell is
composed proteins, DNA, carbohydrates and many other molecules which are
all composed of carbon atoms. The carbon atoms are responsible for the
endless diversity of organic molecules. The most common elements attached
to the carbon are the hydrogen, oxygen, nitrogen, sulphur and phosphate. I
would suggest you look in an organic chemistry book if you would like more
details.

Question5: Why did you decide to study whales?

Dear Aaron,
When I was very young, my father use to take the family by the St. Lawrence
River most Sunday during summer time to eat ice cream and look at boats and
belugas (or white whales) at the main Marina of our county. At about 15
years old, a journalist, friend of the family, asked me to come on a
whalewatching trip to help him with all his camera equipment. On that trip,
I saw belugas, fin, minke and the incredible blue whale. It was an
incredible adventure which I still remember in details. I always wanted to
be a biologist or ecologist, but that day, it was then clear in my head
what species I wanted to work with.


Question6: How do you shoot the harpoon that gets skin samples?

Dear Lindsay,
First, I would not call it a harpoon but an arrow where the tip made of
stainless steel has been modified. To get the skin sample, we shoot the
arrow at the whale with a crossbow. The main biopsy target is just below
the dorsal fin on the right side, so it doesn't hurt the whale.  The arrow
has a float molded to the arrow which is usually of a bright color, so it
makes it easier to collect on the sea. Finally, the dart, a cylinder very
sharp at the leading edge, has barbs inside in order to retain the sample.


Question7: Is there anything in baleen besides what our fingernails are made of?

Dear Cynthia,
All I know about baleen plates is that they consist of a dense cortical
layer of keratin (the protein found in our fingernail and also the hooves
of horses & cows) surrounding 3-4 layers of horny tubes. Sorry!

Quesion8: How do you study molecules? What machines do you use?

Dear Leah,
How and what machine you use to study molecular biology depends on the
researcher interest. In my study, I decided, in a first part, to determine
the exact sequence of the mitochondrial DNA. In order to do that, I use
mainly two techniques. The first is the polymerase chain reaction (PCR).
The machine use for this technique is called a thermocycler which permits
to make millions of copies of a specific fragment of DNA. The second
technique which requires some equipement is gel electrophoresis. You need a
plastic box with at each end two electrodes (positif and negatif). A gel
(agarose gel) is made with some slots for the PCR fragments. It is then run
into a gel through a electric courant. The DNA is negatif, so it is
attracted to the positive side. The gel is then dye to mark where the
specific enzyme has occurred and finally a picture is taken. Today, there
is a lot of fancy equipment simplifying the work coming out all the time.


Question9: What happens to whales when lightning hits the water?

Dear Emma,
This is a very difficult question to answer. All I can tell you is that
whales beside their acoustic echolocation skill, they have sensory
abilities such as magnetic, tactile, electroreceptive, pressure and
gravitational senses. So, it is possible that the whales react if a
lightning hits the water close to them. Usually, when there is bad weather
biologists are back home looking at the data they have collected during the
better weather days.

Question10: Why are whales so big and eat such small food ?

Dear Nicole,

The reason why large whales feed of small food is in fact the result of
many fascinating nutritional adaptations during a long long... evolution.
In fact, the baleen plates are one of the adaptation that allows a really
large animal (such as a fin or blue whale) to eat animal low on the food
chain such as krill (main food for the blue whale) or schooling fishes.




Martine Berube
Dept. of Ecology and Evolutionary Biology
University of California
Irvine, CA, 92697-2525
PHONE:714-824-8680
FAX:714-824-2181
E-mail: martine@newt.bio.uci.edu