Effects of Salted Liver on Planaria (Zoology Experiment)

Essay by sandwichezCollege, UndergraduateA+, February 2005

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This experiment tests the behavior of planaria towards a slice of salted liver versus an unsalted slice of liver. Although eight subjects did not respond at all, a total of thirty planarians moved to either the salted or unsalted slice of liver with a slight favor of sixteen individuals preferring the unsalted slice.


Planarians cannot regulate their internal pressure against that low of a salt concentration. (Champion) This study tests the sensory and response of planaria. Although this simulation is not what these animals would encounter in nature, it will give us a general idea of their sensitivity and behavior that is common in the wild. My hypothesis is planarian will be more likely to move toward the salted liver if given a choice between salted and unsalted liver.


For this experiment I used starved, live planaria that were on average approximately one half inch in length.

Forty-four individual planaria were collected carefully using a wet one-inch paintbrush then transferred to a petri dish filled with pond water. Since chlorine and fluorine are found in tap water, and are hazardous to planarians, pond water was used throughout the experiment as a medium for the animals. (Jonathan) I then set up a controlled experiment where a pea-sized slice of unsalted raw liver was placed to the side of a petri dish half full of pond water. One at a time, a planarian was introduced to the middle of the petri dish. After a response was recorded, the planarian was removed from the petri dish and placed in a fresh dish with pond water where it remained for the duration of the experiment. This procedure was tested for a total of three trials. Next a pea sized slice of liver that was covered with table salt was placed to...