- Oil (to see what affect it has on the mucus)
- Water (to see what affect it has on the mucus)
- Ruler
- Protractor
- Snail
Method
- Weight the snails and label each one (mass in grams)
- Put snail number 1 on surface A at 10 cm away for the central point and wait for a minute or two for the snail to stick to it.
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Hold the surface at different angles for 30 seconds at a time then move angle. First 30°, then 45°,60°,75°,90, 105° and 150°.
- Do the same with the 4 other snails and stick them each separately to the 5 different surfaces (in total 25 experiments).
Results:
Conclusion:
To conclude we have proved that the power of a snail’s mucus is strong enough to hold it on a solid surface until 150°. However on an oily or a wet surface the snail’s mucus wasn’t strong enough to hold the snails at steep angles. The three bigger snails held on to the wet surface until we adjusted the surface to 60° (held on until 45°). We proved that, as we predicted in the hypothesis, if the surface was smooth (oily and watery) the snail couldn’t grip onto it, but if it had a texture it could.
On the first surface, plastic, all the snails held on until 150°. We concluded that this is because the surface was a little rough, so that the snail could grip it and hold on to it. On the second surface, Styrofoam, all the snails held on the same as the previous experiment. Since Styrofoam is a rough surface we also understand that the snails could grip on to it due to the texture and roughness of the surface. On the third surface, a thin layer of soft foam, the snails also held on until 150°. We also contribute this to the fact that the surface has a texture and the snails can grip onto it. For the fourth surface, the rough plastic with the oily surface, only one out of the five snails gripped on at a 30° angle, from what we can conclude that oil prevents snails from gripping onto a surface. We think that this is due to the fact that oil is greasy and a snail’s mucus needs a surface which is rough or has a texture. For the last experiment we had a plastic surface which was covered with cold water. All the snails held on, at the 30° angle but at the 45° the two lighter snails (snail 1& snail 2) couldn’t hold on, and slid down the plastic. We suggest that this is because the two small snails aren’t as strong as the bigger ones; even if they are smaller the mucus is less strong because they are not fully grown yet. Also since the larger snails had a larger area of mucus (due to their size) on the surfaces the mucus holds them on better.
Evaluation:
With this experiment we had experienced quite a lot of mistakes. Firstly we didn’t measure any values we just conducted an experiment with yes or no answers, we could have changed this if our aim was different, for example How much weight can a snail’s mucus hold without letting go of different surfaces with different weights attached to it. Secondly we should have gone until a 180° angle, to see if the snail would fall of the surfaces if it was upside down. Thirdly when measuring the angles we couldn’t be exactly precise because our hand even if still, moved a little bit up or down, creating the error of 5°. We could have corrected this with a stand and a larger protractor. Also another thing we forgot about was that different species of snails might have different mucus and therefore different strengths of mucus. If the experiment had to be repeated it would be advised to use one specie of snails. Also we should have given the snails more time to try to grip onto the surfaces, the only problem with that is that the snails are moving animals, and a couple tried to run away when we left them for a few minutes more.
If I were to repeat this experiment I would actually avoid using any animals, I would advise the group to choose a non-living item. But if the rest still wanted our Group 4 to focus on snails I would pick an experiment where I would be measuring for example the average speed of a snail or how strong the snail is using weights.
