| MadSci Network: Zoology |
Dear Stephanie Keen & Nicole Souza
That is an interesting question. It is true that the starfish does not have a real brain. It does have a well developed nervous system with thoudands and thousands of nerve cells. This nervous system enables a starfish to do all the tasks it has to do: search for food, feed, find a sexual partner, and orient itself. It can even learn.
It is also true that it has no heart. But it is small enough not to need one. All nutrients can reach every part of the body by simple diffusion. It does not need a real blood vessel system.
If you are interested in some more information try:
http://fig.cox.miami.edu/~161hon2/temp1.html
http://www2.cdepot.net/~sci1/amador/bio97/Bio2nd/galli.htm
(But the information offered just scratches the surface - you are probably better off with any good book on invertebrates in the sea.)
Try the links in the MadSci Library for more information on Zoology.