To Catch A Predator (And Use It In Lab Experiments)

Say hello to the newest member of our Biology 326 class: Lucky the Lobster.

Lucky The Lobster     Photo Source: North Shore News

Lucky was recently caught by a Vancouverite off the coast of Bowen Island and donated to our lab (more details about the discovery here).

However, unlike the man who caught it, Lucky is no local. In fact, as an Atlantic Lobster, Lucky is far from home, and is what is known as a non-native species.

Non-native species are species that are present in an area outside of their natural living range. Often, these species arrive via either intentional or accidental human activity. Sometimes, these species have serious negative effects on local species, due to the fact that most local species would be inexperienced in dealing with them; as a result, the local species would have not have adapted any traits to help them fight or compete with the invading species.

While Lucky’s presence in our waters was potentially harmful to the locals, its presence in our lab is fortuitous.

Using water collected from Lucky’s tank, we were able to investigate both native and non-native predators, and their interactions with native and non-native species.

To perform our experiments, we cast Lucky in the role of the non-native predator and Big Dan the Dungeness Crab as the native predator. We also used two snail species as prey: Littorina littorea (a.k.a. periwinkle snails) as the non-native and Chlorostoma funebralis (a.k.a. black turban snails) as the native species.

Photo Source: Brandon Lee

Black Turban Snail                                                          Photo Source: Brandon Lee

Our goal: find out which predator each species of snails thinks is scarier.

To find out just how scary Lucky and Dan were to Littorina and Chlorostroma, we placed individual snails in separate bottles filled with water that smelled like either Big Dan or Lucky and timed how long it took the snails to crawl out of the bottles (assuming that by crawling out, the snails were trying to run away from the smell of the predators).


Photo Source: Brandon Lee

What we thought would happen was that the native snails would try to get away very quickly from the water that smelled like Big Dan, since Big Dan is a native predator. We also thought that the native snails wouldn’t try to escape as quickly, or even at all from Lucky, since Lucky is a non-native predator. Additionally, we expected the non-native snails to be scared of Lucky, but not afraid of Dan.

As it turns out, our results didn’t exactly match our predictions

The periwinkle snails were actually more afraid of Big Dan than they were Lucky, while the black turban snails didn’t really seem to be significantly more scared of either predator.

Things may have not turned out the way we thought they would, but in the end, we were still pretty lucky to be able to work with Lucky.

To learn more about marine predator-prey relationships, check out this documentary:

Or, if all that talk about lobster just made you hungry, learn to make this tasty dish:

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