While exploring the dark, damp redwood forest floor today, it was hard not to notice the vibrant yellow coloration of Banana Slugs. While often bright yellow, they are also sometimes spotted with brown, looking like an overripe banana.
Not only are they colorful, but they are the second largest terrestrial slug in the world, growing up to nearly 10 inches. Here’s a photo of one taken next to a nickel for a size reference.
They use two pairs of feelers to sense their environment. The larger, upper pair, termed “eyestalks,” are used to detect light or movement. The second, lower pair are used to detect chemicals. The tentacles can retract and extend themselves to avoid damage. Slugs have a respiratory hole for breathing on one side (almost always on the right) of their bodies.
Slugs are mollusks and because they don’t live in the water, dehydration is a major problem for them. For this reason they secrete protective slime to keep from losing water.
Some people regard slugs as slimy, disgusting garden pests. But not everyone sees them that way. UC Santa Cruz has adopted the banana slug as their mascot. The students’ embrace of such a lowly creature was their response to the fierce athletic competition fostered at most American universities.
By consuming dead organic matter, slugs contribute to decomposition and the nutrient cycles and are an important aspect of the ecosystem. Here’s a Banana Slug eating a banana peel on a trashcan in a State Park.