During this week’s Biology 326 lab we examined the impacts non-native species can have on native species and their ecosystems. Non-native species are those which brought into a new ecosystem and are able to survive there for at least some amount of time. These species can have negative consequences on the native species as well as the ecosystem if they are able to establish and spread, and in this case they are termed invasive species.
In the part of the experiment I found interesting we used two species of snails, Chlorostoma funebralis (aka the black turban snail) and Littorina littorea (aka the common periwinkle). The periwinkle is a native species of the Pacific, whereas the black turban snail is a non-native species from the Atlantic. Both were exposed to water in which two predators had been kept in. We are able to use water because the snails are expected to be able to detect chemical cues that are left by the predators. The predators in our experiment were a native Pacific Dungeness crab (Metacarcinus magister aka Big Dan) and a non-native Atlantic lobster (aka Lucky the Lobster).
We expected that the black turban snail would be scared of its’ native predator, Big Dan, while the periwinkle would be scared of its’ native predator, Lucky the Lobster. However, what we found was definitely a surprise to me. The black turban snail was not particularly scared of either of the predators, while the periwinkle was scared of Big Dan. What was even more interesting was that the periwinkle wasn’t scared of Lucky the Lobster either. Does that mean Lucky isn’t a predator? Hmmmm. My guess is that Lucky might not be capable of secreting a strong water-born stimulus or it only does so when it is able to see its’ prey. Kind of like how we salivate when we see something delicious. Either way, Lucky the Lobster seems to be pretty lucky if his prey isn’t scared of him.
And by the looks of it, neither are we scared of Lucky and his siblings. In fact, we find them yummy.
On a more serious note, this raises an interesting question. What other experiments can be done in the lab to help us decipher whether there is a predator-prey relationship between native and non-native species besides testing for chemosensory responses? We have already tested for tactile response in another part of this experiment and found that there was no difference in the reaction to the two predators. I hope to discuss this in our Biology 326 class and come up with new experiments.