Gastropods are the least changed from their ancestors. There are almost 40,000 described species in the world and they occupy almost every type of habitat on earth. Equally diverse is their feeding habits, their shapes, their colors, and their sizes.
Agriolimacidae (Terrestrial Slugs)
Meadow Slug — Deroceras leave
AKA Marsh slug, Brown slug
This is a family comprised of small slugs that have no shells. It is the largest family of slugs and species can be found worldwide. This family is mostly herbivorous and some have reputations for being garden and ag pests.
A very small, terrestrial slug, it has become quite common around the world and has adapted to a variety of habitats but does require wetter areas. This little one was “slugging” across the timber steps between the herb garden and the rose garden. It was going the wrong way since the herb garden provides a wetter environment! Most slugs in Wisconsin on non-native. I wonder why this is?
Milwaukee Public Museum has a good listing of Gastropods with info and some photos of slugs that have been identified in Wisconsin.
Terrestrial Mollusk Tool has some good info on slugs and other mollusks