Sluggin' Along: Meet the Slugs

Allow me to introduce you to the slugs that inhabit our backyard. They are members of the species Lehmannia valentiana and are also known as Three-band Gardenslugs because of the stripes on their bodies. You can read more about them here: Factsheet for Lehmannia valentiana.

How did I become interested in slugs, you might ask. Well, we have a 5-month-old Sheltie named Katie, and I have to take her outside at least once a night. A few weeks ago, while I waited for her to take care of business, I would have a look around the yard. That's when I discovered the wonderful night life that I'd never seen before. Slugs would be crawling all over the porch and the walls of the shed, crickets of all sizes would be hopping about and chirping, the ever-present cockroaches would be scurrying to and fro, and the occasional spider would be lying in wait for a nighttime meal. At first I was disgusted by these slugs. I had never heard anything particularly pleasant about them, and they were too slimy for my liking. One night, however, I came upon a bizarre sight: two slugs had coiled around each other, forming a knot on the side of the shed. Regardless of my lack of scientific knowledge, I knew them to be mating. (I checked online just to be sure.) Unfortunately I didn't have my camera with me (why would I want to photograph a slug?). But that one encounter changed my mind about slugs. I no longer saw them as icky, slimy, dumb beings, but as beautiful and mysterious. There was something God-given and harmonious about this silent mating ritual.

Subsequently, I began to research the mating practices of slugs, as well as their anatomy. For starters, here are a few photographs so that you can get to know them. I will discuss the aforementioned topics later on.

It's amazing how flexible the slug's body is. It can coil around almost anything. Also notice the stripes on its body, giving it the name "three-banded."

In this photo, you can see a hole on the right side of the slug's mantle. This is called a pneumostome, the pore through which the slug breathes. The air filters through the inside of the mantle. There is no single organ acting as a lung; instead the vascularized interior of the mantle acts as a lung. When the slug is dehydrated, the pneumostome closes more frequently and stays closed longer. The opposite is true when it is hydrated.

Here you can see a white portion below the slug's body. This is called the foot. Nerves and vessels run into this portion which acts as a large muscle to help the slug move. Notice also the two sets of tentacles: the cephalic (attached to the top of the head, containing tiny eyes on stalks), and the oral (attached to the mouth). Muscles inside the slug's head can retract these tentacles, often for protection.

It looks as though the slug would need legs to climb, but it doesn't! The parts of its body work together as a large muscle, much like a fish swimming through water.