You may be asking yourself, “What in the world is this?” Hopefully all will become clear eventually. In experimental marine ecology class, we are setting up an experiment to see how snails react to the presence of crabs. You see, crabs love a little escargot whenever they can get it. But the snails have ways of dealing with this. They will thicken their shells and change their behavior if they smell crab chemical cues (aka. pee) in the water. These are known as inducible defenses, since the snails don’t bother with them if crabs aren’t around.
An important part of any scientific experiment is measuring things. Here we are measuring snail shell masses. Since the snails are in water, only the mass of the shell is measured, the meat is neutrally buoyant in water.
These are our snails. Little do they know what awaits them next!
Muahahahaha! Here we are drilling on the little snails. What did they ever do to deserve this? Well, the basic idea goes something like this–if the snails react to crab pee, how much more will they react to part of their shell breaking off, as if a crab had unsuccessfully tried to crunch their shell open. Don’t worry, we didn’t hurt the actual living part of the snails, just take out part of the edge of their shells.
This is our experimental setup. Each little tub has a snail, some mussels for the snail to eat, and some have a crab in the second compartment to provide crab pee. Our experiment has a few weeks to run, but don’t forget to stay tuned for the exciting conclusion!