Body temperature.

From: Greg Early (gearly@neaq.org)
Date: Fri Sep 29 2000 - 14:08:31 EDT


Maureen,

This is actually a pretty tough question that had scientists stumped for a
surprisingly long time. The problem is that marine mammals are wrapped in
a protective layer of insulating blubber. Good for keeping cold out, but
also a problem because heat created by muscular activity is stuck on the
inside of the insulation. The catch is that marine mammals control the
temperature of different regions of their body and dump heat off through
their fins and flukes. So "average" temperature may mean different things
in different locations on their body. In fact recent studies have shown
that dolphins keep certain areas inside of their abdomen (where their
reproductive organs are) cooler than the rest of their body. Having made a
confusing mess out of a relatively simple sounding question, the short
answer is , that if you average out all of their body temperatures, marine
mammals are in the normal range for most mammals (around the usual 98.6 ish
range).

Tuna, on the other hand, recycle some of the heat generated by muscular
activity, and use it to keep their bodies slightly above the temperature of
the water they are in. Quite a trick if you consider how much of their
surface area is exposed to cold water (gills have a huge surface area to
extract oxygen from the water). So, yes in a sense they are homeotherms.

ge

 At 09:28 PM 9/27/00 +1200, you wrote:
>1. Whales are warm blooded but what is their average temperture?
>2 Are tuna fish homeothermic too?
>Thanks
>Maureen Coxhead
>coxheadmm@xtra.co.nz
>



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