Subject: Lungs and blue whales

Dagmar Fertl (Dagmar_Fertl@mms.gov)
Tue, 29 Dec 1998 13:49:15 -0500

     I will be most obliged if you could provide me with this info?  What 
     is the reserve lung capacity of  a blue whale?
     
     My e-mail address is "Sudheer" <pipl@vsnl.com>
     ____________________________
     
     Hello there.  Your question had me rifling thru some of my marine 
     mammal reference books at home during lunch today.  Pardon me for a 
     long explanation to your question, because I'll need to refresh your 
     biology/anatomy terminology.  
     
     First, there is no such term as "reserve lung capacity".  I believe 
     what you are asking for is "residual capacity", which refers to the 
     gases in the lungs that are not fully exchanged during a breathing 
     (I'm assuming you understand the basic principles of exhalation and 
     inhalation).  Humans during breathing only exchange 10-15% of the air 
     in their lungs with each breath; whales and dolphins have a much more 
     efficient exchange of air at 80-90%.  The lung capacity of a blue 
     whale of course depends on its size, but will probably be a maximum of 
     2,000 litres of air (this compared to the max of 4-5 litres of air for 
     a human).  What's interesting is when you look at the ratio of maximum 
     lung capacity to body weight (compared to terrestrial mammals), a 
     rorqual's (like a blue whale) ratio of lung capacity to body weight is 
     half that of its relatives on land.