Aliens in the Classroom

Royal BC Museum – Where the Past Lives

Aliens Among Us

Slugs

Melissa Frey, Curator, Invertebrates, Royal BC Museum

My name is Melissa Frey, Curator of Invertebrates at the Royal BC Museum.  You identify a Giant Garden Slug typically by it’s size for one thing, they are large, they can measure somewhere between 10 and 20 centimeters.  Although these individuals are a little bit smaller.

In terms of their colouration, their colouration can vary, but they tend to be brown to grey in colour.  They’re mottled with these black to dark brown spots all the way along their body. 

They have a region called the mantle, which is up here near the head, and this mantle has little tiny concentric ridges or folds which, if you look closely enough you can see those.   This is characteristic of this species relative to something like the native Pacific Banana Slug because the Pacific Banana Slug has on the mantle, little tiny granules. 

The other thing about the Garden Slug here is that you can see here on the right side of the mantle, it is an opening.  This opening is called the pneumostome, and the pneumostome is what they use to breath out of.  The location of this pneumostome is slightly behind the midline of the mantle posterior.  So that is another characteristic that you can use to key out the Garden Slug. 

The Giant Garden Slug, like many terrestrial snails and slugs that have been introduce to BC are typically considered pests.  We don’t always know exactly how they interact with native snails and slugs but one of the trends that we tend to see is that in regions that these species are introduced we tend to see a decline in the native snails and slugs in that area. 

Royal BC Museum – Where the Past Lives

Museum Moments

It’s often been said that our oceans are our last and greatest remaining natural mystery on planet Earth.  This past year, BC’s coastline became a little more mysterious. 

Hi, I’m Connie Mitchell here at the Royal BC Museum with Jim Cosgrove.  Take a look at this, Jim what is this? 

Connie, this is a Humboldt Squid, also known as a Jumbo Flying Squid and last year, for the very first time,  these appeared in British Columbia’s waters.  Full size, this animal can be the same as my size, six feet tall and 200 pounds.

It typically feeds on fish, it’s also cannibalistic so they will eat each other and they have the potential to be dangerous to humans. 

Really, how so? 

Well, let me show you.  Take a look in the microscope Connie.  These are the sucker rings and they actually have teeth on them. 

Wow, they’re beautiful but they do look dangerous.  So, what is the mystery Jim?

Well, the mystery is why did these animals come to British Columbia.  Typically they live from Mexico down to Tierra del Fuego in South America.  But last year, they were here in the tens of thousands for the very first time. 

Do we know why?

It may be warmer water, it may be that they were displaced by larger animals further south, it may be that they were chasing a particular food source.  A number of possibilities.  We’ll have to wait until maybe this year to find out why. 

Every year, the museum’s scientists and research partners conduct detailed inventories about BC’s plants and animals including ocean life.  This is just one more of the mysteries they are working on. 

You can uncover your own mysteries in person or online at www.royalbcmuseum.bc.ca.