StoryImage( ‘/Images/Story//Auto-img-11382207427078.jpg’, ”, ‘A very large group of animals There are more than 80,000 species of snails and slugs. These gastropods belong to the group of animals known as molluscsa phylum that also includes clams, oysters, and the octopus and squid. Of all the molluscs, only snails and slugs can live on land. The largest snail is the Giant African snail, with a shell reaching 11 inches. (This creature is often illegally imported into the U.S. as a pet; it has a significant risk as an invasive pest and a carrier of dangerous parasites.) Several tiny species of land snail compete for the title of smallest, at just a fraction more than 1 millimeter in size.’);
StoryImage( ‘/Images/Story//Auto-img-11382207797064.jpg’, ”, ‘One of our regions tiniest snails Gastrocopta tappaniana is less than ‘);
StoryImage( ‘/Images/Story//Auto-img-11382208147077.jpg’, ”, ‘Iowa Pleistocene Snail Discus macclintocki was first discovered as an Ice Age fossil, believed to be extinct. Then in 1940, this snail was found alive in Iowa. Although endangered, it survives in isolated habitats in our region.’);
StoryImage( ‘/Images/Story//Auto-img-11382208558060.jpg’, ”, ‘Fossil gastropods The shells of 450 million-year-old sea snails are perhaps as common’);
Snails and slugs quietly succeed in natures survival of the fittest
Some people are disgusted by these slimy creatures, while others find them entirely fascinating. As one of the longest-lived groups of multicellular animals on earth, with ancestors living half a billion years ago, snails and slugs deserve at least a little respect. These creatures belong to the class of animals known as gastropodsa scientific name meaning stomach-foot, referring to the way they crawl along on their bellies.
Snails typically have spiral shells that are either flattened or long and spired, while slugs are actually snails with only a tiny piece of shell imbedded in their flesh. The biology and lifestyles of snails and slugs are similar. On land, they ooze along on trails of mucus, living on a diet of dead or living vegetation. Theyre usually found in moist earth or plant debris, especially in woodlands.
In our region, land snails are quite small, from the size of a pinhead up to an inch in diameter. To find them, the easiest thing to do is sort through a pile of plant debris or turn over a rotting log. They can even be found in the winter, hibernating under the soil. Like many of the other creatures youll find in this habitat, snails and slugs are important decomposers. They break down dead vegetation so its nutrients can be reused. Snails are also an important food source for insects and other arthropods, frogs and toads, snakes, turtles, birds and mammals.
Despite their invaluable service as natural decomposers, snails and slugs have earned a reputation for being pests when it comes to gardens and lawns. As garden pests, they indulge on the most succulent parts of plantsyoung sprouts and shoots, flowers, and fruit.
From the Jan. 25-31, 2006, issue