Banana slugs are essential to a clean and healthy rainforest.

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“It does not taste like a banana! It’s a banana slug, but that slimy thing does not taste like a banana, trust me.” That’s how it started with my seven-year-old daughter. “Well, the slime has to taste like something. It’s probably banana flavoured, you should lick it.” I challenged. “No way! I’m not licking that little guy, he’s way too slimy. You lick it first, dad!” Well, she had me there. I wasn’t going to lick it either, so we never did find out the flavour of slug slime. But we did learn a couple things about these little forest critters.

First, “little” in the world of slugs isn’t quite accurate. A British Columbian banana slug (aka, pacific banana slug, or Ariolimax Columbianus for our fact checking readers) is actually one of the largest land molluscs in the world! Wait “land” mollusc? Didn’t we cover various molluscs in our summer marine blogs? Don’t molluscs live in fresh and saltwater? Well, yes. However, land molluscs like the banana slug are also a reminder that aquatic life has adapted to terrestrial living over time. A small hole on the side of its mantle (i.e., what you would note as the head) inhales and exhales air which passes through an internal gill; an evolutionary biological feature that evokes fascination and questioning wonder about the transition from marine to terrestrial living.

However, this slug is not to be messed with! If you were decaying foliage, rainforest poo, a mushroom, or just regular understory junk, the banana slug’s 27,000 teeth would be enough to scare you! They basically eat almost every piece of natural garbage below a rainforest canopy and are essential parts of a clean and healthy rainforest ecosystem. Some of these slugs are completely yellow, some are brown, and some are yellowy-green with spots (just like a rotting banana). Colour is dependent on each individual slug’s genetics, sun exposure, and moisture content. Oh moisture! This is the part where we get to talk about the slime.

If you pick up a banana slug without gloves your fingers will be covered in slime. And you basically can’t get it off, even with soap and water. That’s because the slime absorbs up to 100 times its volume in water! Kinda like throwing a whole roll of toilet paper into the crapper. But a banana slug can’t possibly cart around a full load of sopping wet toilet paper rolls, so what does it do? Instead, it secretes small dry granules of mucus which then absorb moisture from the surrounding environment. The resulting slime is then used as a natural lubricant to help the living foot-like muscle glide along the forest floor. Which is why slugs are almost always found in moist environments. What does that slime taste like? If you hold the slug with bare hands for too long your fingers will start going numb from the natural antiseptic solution in the slime itself. Imagine being a predator. After one experience of a numb throat and super dry and numb mouth and tongue, a slug wouldn’t be your first choice for a meal. As a human, unless you need emergency rainforest dental work you shouldn’t take up slug licking as a hobby. But there is one hobby you can take up – slug racing!

A banana slug can travel up to 6-6.5 inches a minute. That might not seem fast, but in the 1980s the Russians reportedly held annual slug festivals to see who had the fastest slug. I’m not quite sure how to train a slug for forest Olympics. However, they live approximately seven years so there’s plenty of time to find an extra slippery slug and train them for the races. Although, with eyes perched at the end of its two weirdly long optical tentacles, the banana slug actually has very poor eyesight. It relies mostly on smell and feel from its lower feelers around its mouth.

There you have it. A 27,000 toothed critter that you could put in the forest races but that you probably shouldn’t start a licking habit with.

Banana slug.

Bryce Casavant is Social Scientist and former BC Conservation Officer. He currently works as the conservation policy analyst at Pacific Wild – a registered Canadian environmental charity. Bryce can be reached at bryce@pacificwild.org

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Photo by Thomas Bonometti on UnsplashVancouver Island rain forest