By Jeff Nekola Young naturalists Tiny Travelers ▼ Known for their slow pace, these nearly invisible creatures live all around Minnesota.

Imagine the Great Plains in miniature: a piece of land the size of a dinner plate with thousands of grazing animals, most no larger than a candy sprin- kle. Each animal has its own portable house. When it comes out to eat, it crawls on only a single foot. These remarkable animals are land snails. Land snails are mollusks, the second largest phylum of animal life on earth. They belong to a group known as gastropods. Gastropods have colonized almost the entire planet, living in places from deep oceans to shal- low coastal waters, freshwater lakes, rivers, and springs. On land, they range from arctic tundra to tropical rain- forests and from deserts to swamps. North America is home to more than 1,200 species of land snails. Minnesota harbors about 90 species. They live on prairies, in forests, and near swamps and rocky bluffs and boulders. Land snails are so poorly known that until 30 years An amber snail, ago only one Minnesota species had a common Eng- Succinea ovalis, crawls slowly across lish name—the cherrystone. While common names a leaf on a track have since been proposed for all, they had to be invent- of slippery mucus ed from scratch and are usually not very useful. So, like produced by a special the names we use for dinosaurs, we’ll stick with Latin gland on its foot. scientific names for land snails in this story. BILL JOHNSON 41 Fun fact Minnesota Snails The word gastropod What’s in the Shell? comes from the Greek gaster, meaning A land snail has a shell large motion that pushes its body Vallonia pulchella stomach. Pod comes enough for the animal to forward. Its foot has a special from the Greek word completely withdraw into it. gland that produces slimy for foot. A gastropod’s Like all gastropods, a land mucus. The mucus makes a foot comes out of its snail has a head with two slippery track on the ground, body near the stomach. or four sensory tentacles. leaves, or other surface for Carychium exiguum The snail uses its tentacles to smoother traveling. A land Vertigo elatior smell—the sense it uses the snail can survive in dry condi- Fun fact most to learn about its world. tions, but it is active only when Land snails without an Some snails also have eyes on it has enough water to pro- outer shell are usually their tentacles. Snails do not duce mucus. called slugs. A semislug have ears of any kind. has a shell that is too The snail has a mouth and a Tiny and Tinier small for the animal to special tongue called a radula. Minnesota’s land snails range in fully withdraw into. The radula is covered with size from the 2-inch Neohelix Strobilops labyrinthicus 1 hundreds of sharp barbs, alleni to the /16-inch Punctum Gastrocopta contracta which work like teeth for eating minutissimum. While you are Fun fact food. The snail gets rid of body most likely to see larger snails Most Minnesota land Mouth Esophagus wastes through the skin or the when exploring outdoors, they Radula snails are slightly end of its digestive system. turn out to be far less common Algae Land Snail Anatomy (food) Teeth of radula larger than Lincoln’s Like people, land snails have than little ones are. nose on a penny. Over lungs and breathe air. Because If you counted all the snails Shell 150 individuals of the of this, a land snail would in the state, these tiny ones smallest species would drown if it fell into water. It has would make up more than fit onto a single penny. a heart but no arteries or veins. 85 percent of them. In some Stomach Tentacle with eye It pumps its blood through habitats, such as white cedar Lung openings between its cells. swamps and limestone cliffs, To move around, the land it is possible to find more than Esophagus

snail has one foot. It contracts 5,000 snails within a single Tentacle and expands its foot muscles square yard—a space about as Heart Mouth

to make a kind of rippling big as an armchair. LITWAK TAINA Radula Crop Foot 42 Minnesota Conservation Volunteer Slime does more than just help this amber snail get around. It makes it hard for mice or birds to get a grip on it. Small parasites may get stuck in the slime. The flamed tigersnail, Anguispira alternata (far right), is one of the most common large snails found in Minnesota.

BILL JOHNSON BILL FRANK What Do Snails Eat? which eats other animals. Haplotrema Most Minnesota land snails are detri- concavum lives in southeastern Min- A Place That’s Just Right tivores, meaning they get food from nesota forests, where it hunts for other dead and decaying plant matter such as snails and worms. An ambush predator, Minnesota land snails live in a variety of When exposed to full sun and dry fallen leaves and rotting wood. Using this snail waits patiently until its prey places, from swamps to dry prairies and air, most land snails quickly die, even the sharp, tiny teeth on its tongue, a comes near and then suddenly lunges rock outcrops. Most live on the ground, inside their shells. If leaf litter, humus, snail scrapes fungi off the plant matter. out from its shell to grab and eat it. especially among moist layers of leaves or other organic matter is removed, Many snail species also happily eat al- under trees and shrubs. They also like the snail habitat vanishes. For this reason, gae and lichens growing on rocks, tree Who Eats Snails? humus (decomposed plant and animal fire is one of the most serious threats bark, and leaves. You might find piles of broken shells matter) that collects between rocks and to land snails today. Researchers have About a dozen of Minnesota’s land where mice and other small mammals on small ledges of cliffs. Many snails live in studied snails on land often burned by snail species are herbivores, which eat have been dining on larger snails. A va- dead plant leaves and stems on the ground fire and on land never burned. When living plants. Among their favored riety of birds also eat land snails. Small- on prairies and land near ponds and other fire destroys snail habitat, about 90 per- foods are nettle leaves, which contain er snails often avoid these threats, but wetlands. These dead plants serve as food cent of individual snails and one-third lots of nutrients. some beetles can rip open a tiny shell, and shelter from sun and wind. of snail species disappear. Minnesota has one snail carnivore, remove the snail, and eat it.

44 Minnesota Conservation Volunteer September–October 2016 45 The earth-colored shell of this Neohelix alleni snail helps it blend into its surroundings and hide in plain sight from birds and other predators.

JEFF NEKOLA The most likely way that a snail will die A Long, Slow Nap is from disease and old age. When the weather is dry or cold, a land Baby Snails snail will fully retract into its shell and Cross-Country Travel go to sleep. To do this kind of hibernat- Most land snails are hermaphrodites, ready to hatch, the baby snail uses its While most snails will move only a few ing, or estivating, a snail pumps as much which means they have both male and barb-covered tongue to eat its way out yards under their own power within their water as possible out of its body and then female body parts. Such a snail does not of its eggshell. lifetime, some travel long distances with seals the opening of its shell with a cello- need a mate because it can fertilize its When the new snail emerges, it al- the help of animals, water, and wind. Mi- phane-like covering called an epiphragm. own eggs with its own sperm. Depend- ready has a small shell, called a proto- grating birds can carry a small land snail It might also glue itself to a leaf, rock, or ing on its species, the snail lays one to conch. Some newly hatched snails may thousands of miles while the snail holds other object to protect itself from the out- 100 eggs. take many years to become adults. Oth- on with its sticky mucus. If you run your side world. When the outdoors becomes A baby snail develops within the egg. ers mature in just three weeks. hand through damp grass leaves, you warm and wet, the snail comes out of its Scientists don’t know how long many Depending on the species, adult might find a few small snails sticking to shell. Some land snails have woken up snail species take to develop. When it’s snails may live from weeks to decades. you and coming along for a ride. after estivating for 70 years or more.

46 Minnesota Conservation Volunteer September–October 2016 47 Pupilla hudsonianum Five Minnesota Land Snails This microsnail has been found on two northwestern lakeshores in Minnesota. Hendersonia occulta (cherrystone) The species was discovered and named in In Minnesota the ¼-inch cherrystone 2015 from the population found at Lake snail lives only in cool, humid rock out- Bemidji State Park. It is a common ice-age crops in the woods of southeastern coun- fossil in Iowa and Illinois. Its range reaches ties. This species is known from ice-age west to the Rocky Mountain foothills in fossils found in areas 100 to 1,000 miles Alberta, Canada, north to Hudson Bay, south of Minnesota. Today its range and east to Newfoundland. reaches from Minnesota and Missouri east to Pennsylvania and Tennessee. Vertigo nylanderi This microsnail was reported from one place in northern Minnesota in 1955. For Gastrocopta rogersensis more than 40 years, nobody found the This land snail is about the size of a grass species alive again. Then, in the 1990s, re- seed. In Minnesota it is found only in dry, searchers discovered it at three dozen co- rocky prairies along the Mississippi River nifer swamps in northwestern Minnesota. in the far southeastern counties. The range Its range extends from Minnesota and of this microsnail runs from Minnesota central Manitoba to Maine. south to Oklahoma and east to Ohio. COURTESY OF WILL PHELPS How to Find Snails The best way to observe land snails is by Planogyra asteriscus searching piles of leaf litter. Put a shal- Very rare in Minnesota, this microsnail low sieve, or strainer, of fine mesh inside has been found in only four northern a slightly larger sieve of extra fine mesh. white-cedar forests along the Lake Supe- Add handfuls of leaves, then shake and rior shore in Cook County. Its range runs tap the sieves to get the smaller par- from Minnesota east to New England ticles to pass through. Examine both a magnifying lens to find and examine states and the eastern provinces of Canada. large and small pieces. If needed, use the tiny snails. nV Teachers resources Find a Teachers Guide and other resources for this and other Young Naturalists stories at CENTIMETER SCALE PHOTOS: THIS PAGE, COURTESY OF MATT PICKHARTZ, BELL MUSEUM MOLLUSK AND CRUSTACEAN COLLECTION; OPPOSITE PAGE, COURTESY OF JEFF NEKOLA, UNIVERSITY OF NEW MEXICO. ENLARGED SHELL PHOTOS: COURTESY OF JEFF NEKOLA, UNIVERSITY OF NEW MEXICO. September–October 2016 mndnr.gov/young_naturalists. 49