Snails at Lux Arbor Reserve

Warning:  As you may see, Lindsay has already done a wonderful job summing up our adventure to Lux Arbor, so I'm sorry if this sounds redundant.  I will try my best to be original. :)

Here it goes!

What is Lux Arbor Reserve? 

It is a long-term ecological research site utilized by Michigan State University.  The site is filled with diverse land and aquatic environments, making it a perfect area for research.

http://lter.kbs.msu.edu/maps/thematic_maps.php

What did we do there?

Using the various bodies of water Lux Arbor had to offer, we studied how predators, such as Pumpkinseed Sunfish, can influence snail size and distribution.  In order to do so, we took snail samples from the various ponds and lakes in order to collect more data on them back in the classroom.  To determine the affects of predators on the snails, we took samples from smaller bodies of water without fish as well as larger bodies of water with fish.

http://www.seagrant.wisc.edu/greatlakesfish/fpumpkinseed.html

What did we find?

The figures below highlight our results:

Figure 1

Figure 2

As seen in the figures, species and size of snails varied between the various types of lakes.  We were surprised to see that the snails were smaller in the larger lake, but once we measured the thickness of their shells, it made more sense.  Although we may not know if their inability to break under pressure was due to their shell thickness or lack of surface area, the data suggests that they may be smaller and "stronger" for many possible reasons.   In the larger lake many of the snails were found under rocks, hence the smaller they are the easier it will be to hide beneath them from predators.  Also, the stronger the snail, the harder it will be for the fish to break it's shell in his mouth.  So, even though the snail may be small enough to attempt to eat, it won't be able to if it can't break through the shell.

Valerie looking under rocks for snails in Lower Crooked Lake.

As for the smaller lakes, their larger size may be due to the fact that the predators are smaller, so they need to be bigger so they cannot be eaten by the small predators.  Also, the smaller lakes were much more dark and mucky compared to the rocky larger lakes, therefore lacking the need to fit under rocks to hide.  Instead, they most likely utilize their dark coloring in order to blend into the muck.

Small snail found in the muck of a smaller lake.

All in all, the fact that the results didn't turn out as one would originally expect made the experiment that much more interesting and educational.  

The End!

- Natalie McHale