Re: CROCODYLOMORPH ENDOTHERMY

[Van and Kathy Smith <vksmith@ix.netcom.com>]

At 10:20 AM 1/31/96 -0500, Dinogeorge@aol.com wrote:
>In a message dated 96-01-31 02:49:11 EST, pharrinj@PLU.edu (Nicholas J.
>Pharris) writes:
>
>>The *most* active fish (sharks, tuna, sailfish) have evolved some level 
>>of endothermy. :-)
>>
>>
>
>Right. But the endothermy surely came later. We're talking about _necessity_
>here. Endothermy should be considered an evolutionary improvement to an
>already active lifestyle.
>
        I have heard about endothermic fish for quite awhile, but have never
been given many details.  Are they like the hawk moth who generates heat by
exercising its massive wing muscles, but when not flying cools down to
ambient temperature (i.e. is their endothermy due solely to heat released
from their powerful swimming muscles)? What sort of heart structure do these
fish have?

  
Van Smith