Preparing a Hypothesis and Protocol for your Snail Experiment

The Hypothesis

You were asked to do some reading on pond snails and come up with a hypothesis that you can test in lab on the assigned experiment day.

This hypothesis should be based on what you observed in regards to pond snail behavior.  You tested nonassociative types of learning called habituation and sensitiziation.  You can propose experiments that enhance or decrease the effects that you measured on tentacle retraction time.

The end of the guide to the snail experiment listed these possible questions.

Sample experimental questions:

1. Does the snail move faster when touched on the tentacle or any other body part? 
2. Does touching the shell affect motor activity or tentacle movement? 
3. How many times do you have to touch the snail before habituation occurs? 
4. How long does it take for the tentacle to extend again after withdrawal in response to tactile stimulation? 
5. Are the effects of habituation restricted to one tentacle? 
6. What effect does the presence of food exert on habituation?  On motor activity? 
7. Does touch the shell or tentacle affect “rasping” behavior? 
8. Does water temperature affect behavior? 

Read pages 19-21 in your Principles of Biology text to refresh your understanding of hypothesis driven science.

The Prediction

Make sure you provide a prediction on how your hypothesis will be supported.  If possible gather evidence that supports your prediction.  Scientists build on the information gathered by others.  You are at the very least expected to build on what you learned in your first snail experiments.

The Protocol

The protocol should include the materials that you will need to perform the experiment.  You should also have a detailed description of how you will carry out the experiment.  How you handle the animals, how many you need (there are limits), temperature of the water (we will need to agree as a class on some of these temperatures), how you poke, where you poke, etc.  Make sure you have controlled and experimental tests. Use the snail experiment that you did to guide you in preparing a good set of instructions for carrying out your

Please be prepared to discuss your experiment with me during the next lab.