Re: What are specific reactions of planarians to different water temperatures?

Jennifer:

     Thanks for your question.  Sorry it took so long to get you an 
answer.  Planaria, like many flatworms are first of all "Cold-blooded."  
So in gross terms, their reactions to water temperature will primarily 
involve their overall rate of metabolism.  This should manifest itself in 
some obvious ways, such as faster swimming, and likely a shorter average 
life-span.
  
     There is also an ideal range of temperatures under which a planiaria 
can live and reproduce, and outside of this range, the conditions will be 
either damaging or fatal.  Most organisms have a set of conditions which 
are ideal to them.  Some bacteria for example are so adapted to living in 
harsh conditions at places like the Great Salt Lake , that they will often 
die when exposed to ordinary water, since they cannot regulate their 
internal pressure against that low of a salt concentration.

     Since Planaria are easy to obtain and 'grow' the questions you ask 
can also be answered by performing some experiments yourself, to see what 
happens when planaria are exposed to prolonged temperature differences.  
You could grow worms at 15C, 20C 25C 30C 37C and 42C and see how they 
react.

A Web Search of Planaria will yield many good sites, I have included links 
below to several that contain numerous facts about husbandry and 
observatiosn on the flatworms.
 http://www.users.voicenet.com/~ginette/plantxt.htm
 http://ebiomedia.com/gall/classics/Plan/plan_links.html

And here are some links specific to temperature effects on Planaria:

Effects of Temperature on Planarian Head Regeneration http://www.bio.davidson.edu/people/midorcas/animalphysiology/Projects/2000P
rojects/Marks-Pleasants.htm
 http://www.scienceproject.com/projects/intro/Senior/SB161.asp


Thanks for your question.

-Matt-