Subject: Manatee breathing

Jennifer D. Philips (
Mon, 04 May 1998 22:15:11 -1000

>We are reading the story Sam the Sea Cow in our second grade class. One 
>of our children wanted to know how a Manatee breathes while it sleeps. 
>We are at Chimneyrock Elementary in Cordova, TN near Memphis.
>Thank you,
> Teresa McClure and Jennifer Stinnett

Teresa and Jennifer - 

Your student has a good question!  The answer is that most marine mammals
that do not haul out of the water to sleep, like the seals and sea lions,
sleep semi-consciously (that's not a technical term, I just made it up).
Basically, whales, dolphins, and manatees (as far as scientist know right
now) sleep one hemisphere at a time, so that only half of their brain goes
to sleep while the other stays awake and monitors such things as surfacing
to breath.  They tend to become very inactive during sleep mode, mostly
drifting and floating near the surface or just below, and when its time to
breath, they just slowly ascend and take a new breath.  Then the other half
of the brain takes its turn sleeping while the just rested half takes over.  

Thanks for your question!  Write back anytime.  

Aloha - 



Jennifer D. Philips

Marine Mammal Research Program
HIMB, University of Hawaii at Manoa
PO Box 1106			
Kailua, HI  96734
voice:  (808) 247-5063
fax: (808) 247-5831