Slugs live all over the wetland and, believe it or not, perform a completely necessary function in our environment. Slugs are invertebrates. That means they don't have any backbone. Slugs are gastropods of the phylum mollusca. There are almost as many different kinds of gastropods as there are different kinds of insects. Some gastropods have visible external shells and are called snails. I'll talk about snails in another issue. Some gastropods have no shells, or only very rudimentary shells, and are called slugs. There are many other kinds of gastropods in addition to snails and slugs, but today I'm only going to talk about slugs. They are totally cool creatures!
In the great Pacific Northwest, we have the second largest land-dwelling slug that exists, the absolutely gorgeous Banana Slug. It's name comes from it's yellow color.
Another familiar slug around here is the rufous, or black, garden slug.
People have two lungs and breathe through their noses. Slugs only have one lung and breathe through a hole in their sides near the front of their bodies. Their eyes sit at the end of stalks that they can quickly retract when they sense danger. These eyes can sense light and movement. But, slugs are also have a second, smaller, set of stalks beneath their eye-stalks, which can sense chemicals. If you make a slug mad or scare it, it can shoot a stream of gooey slime in your direction.
Slugs need to stay moist, so they usually stay hidden beneath leaves, logs, rocks, and just about any other cool, damp, dark places, coming out at night to feed. If the weather is very dry, they can cover their mucus-coated bodies with dirt, leaves, and other insulating materials and stay dormant until the weather conditions improve.
Another interesting thing about slugs is that they're hermaphrodites. That means that there are no male or female slugs. Slugs are both male and female at the same time. And, like snakes and birds and amphibians - slugs lay eggs. Lots and lots of eggs. A single slug can lay anywhere from 20 to 100 eggs at a time. That's a lot of slugs!
Slugs are very important to our environment. They eat things that most creatures would never think of eating, like dead leaves, feces, and mushrooms. What comes out of the other end is a beautiful, rich humus that revitalizes the forest floor. So, they're really rather neat little composters. Bad goes in one end and good comes out the other.
Not only do slugs clean up the bad stuff and deposit the good stuff, they're an important food source for other creatures living in the wetland, such as: raccoons, snakes, ducks, geese, and salamanders. And that brings us to a very interesting question: How do these animals eat a slug without gluing their mouths or beaks closed? We've all had slug slime on our hands at one time or another and know how difficult it is to get off. And, anyone who's neglected to clean their tools or clothing immediately knows the permanent nature of dried slug-slime. So, how does a goose eat a slug? He carefully rolls the slug around in the dirt first to solidify the slime, then quickly gulps it down. Yum!
The next time you see a slug in the park, remember what a useful creature it is. You might not want slugs in your garden, but we love slugs in the wetland!
Teri Lenfest
Fascinting info! Great pictures.
Posted by: Adele | April 06, 2010 at 05:46 PM
Go Santa Cruz, go!!!
Posted by: nato | April 06, 2010 at 06:02 PM