I FOUND A PLANARIAN!!!!!!!

Forty-one  years and approximately 1,000 aquatic ecology programs and nothing has thrilled me more than standing on the pouring rain by the Big Thompson River this afternoon with a group of AP biology students!!!!! The whole reason for my excitement is one tiny little planarian.  If your thinking the word planarian sounds familiar, but you do not know why cast your mind back to either Jr high school science class or high school biology class and a little experiment you may have done where you tried to make a worm grow two heads or two tails.

Need a refresher on what they look like? Check out the YouTube video. 

According to most published sources you can find these little flatworms in any body of water, but they are not obvious at first.  They are not kidding about that either finding a planarian whose maximum size is .5 inches long is no easy feat.  When I turned over the rock under which the little worm was hiding I though it was merely a baby leech until I saw it move in the little pool of water stuck in the crevice.  It appeared to be undulating not moving with an accordion like movement.  After putting our creature under a magnifying glass I confirmed it was indeed it was a flatworm. 

In my excitement I showed it to the students and told them what it was.  "We just did experiments on them in science class" one student remarked. "
"Oh, were you making two butts or two heads?" I asked.
"We tried both but they all died" was the most common answer to my inquiry.
Here is the experiment they tried:

Planarian regeneration

For students who are interested, they may perform a regeneration experiment. Have the students use the magnifying glass to observe the planarian in a Petri dish.With a coverslip, the students can then cut the planarian at a certain point(s) to create 2 or more planarians. Over the course of several days, they can monitor the planarians’ regeneration and see for themselves how efficiently the planarians can regenerate lost body parts.

Why does it work you ask?  Well, I will let the good people at the Encyclopaedia Britannica explain that for me:

         "There is evidence that a special type of cell, a neoblast, is involved in planarian regeneration. Neoblasts, rich in ribonucleic acid (RNA), which plays an essential role in cell division, appear in great numbers during regeneration. Similar cells, apparently inactive, occur in the tissues of whole organisms (see also regeneration: Biological regeneration)."

This is what they might have looked like had the students or my planarian  lived to regenerate.

                                                  
SO COOL RIGHT?!! Chop the little guy into three pieces and you would get three new planarians, but cut just part of it and you have a really creepy two headed creature.This same experiment was tried on the International Space Station a number of years ago to see how well they regenerated in zero gravity.

Hiding in the shadows of a body of water near you Frankenstein's pet.


Here is some more weird and funny information on planarians:

http://neuron.illinois.edu/files/LP_PlanarianExperiments_outreach.pdf
http://ase.tufts.edu/biology/labs/levin/resources/documents/PlanarianManual.pdf
http://www.brighthubeducation.com/science-lessons-grades-9-12/36527-planaria-regeneration-experiment/