Alien Species Among Us

It’s true, alien species are all around us, even in our own backyards. Now don’t panic, by alien species I don’t mean little green beings from a galaxy far, far away, but instead plants and animals that have been introduced into a new environment and made themselves at home. The term ‘alien’ simply refers to an invasive species, or one that is not native to its current location. Sometimes invasive species are purposely introduced for aesthetic reasons for example, English ivy being used for building coverage – we’ve all seen buildings blanketed in a dense layer of ivy, and sure it adds character, but this ivy can be extremely damaging to native species by essentially smothering other plants of sunlight.


While invasive species can be introduced in many different ways, the thing that decides whether they are here to stay is their ability to survive in the new environment. Species that are able to thrive in a wide range of environmental conditions will be better equipped to live in a location they are newly experiencing.


Plants aren’t the only invasive species, aquatic organisms are often transported from one body of water to another through human activity


For my final project, I chose to study the invasive species Caprella mutica, which is a species that has been introduced to B.C. by basically being a stowaway in the ballast water of transport vessels.


Although Caprella mutica is an Earthling, it does share an uncanny resemblance with the coffee loving aliens from everyone’s favourite Will Smith movie, Men in Black

I tested how this invasive species responds to changes in temperature and salinity by observing whether their heart rate was altered with these changes. To sum up a three-week experiment in a few sentences, what I found was that when temperature increased the heart rate of these individuals increased, while changes in salinity had no effect on heart rate. Now an increase in heart rate might not seem that bad, but if temperature increases further the animals heart may not be able to keep up, a prolonged rapid heart rate can actually be damaging to an animal. Your heart rate is set at a steady rhythm when at rest to minimize energy use and maximize lifespan, this is the same for other animals as well.


Be still my heart! You can actually watch a caprellid’s heart beating under a microscope thanks to its transparent body wall.

So now we know this species is affected by changing temperatures by why does this matter? Considering this is as invasive species that has established itself in many parts of the world and that it has the potential for impacting native ecosystems in a negative way, it is important to know what environmental factors could determine the distribution of this species. With the knowledge of what environments this species could survive in, we can predict where this species could invade successfully in the future, and possibly take action to mitigate this.

Here are some tips on preventing terrestrial invasive species that everyone can do!


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