Banded Mystery Snail – Oneida County Aquatic Invasive Species Program

Banded Mystery Snail (Viviparus georgianus)
Help protect  Wisconsin’s   lakes and rivers by preventing their spread.

Why are we concerned?

  • It competes with native snails for food and habitat.
  • It serves as a host for parasites that can be transmitted to fish and other wildlife.
  • It can invade largemouth bass nests and significantly increase the mortality rate of the eggs. Banded mystery snails are also known to consume fish embryos.

How does it spread?
Some banded mystery snails are released from home aquariums, and others are transported by boats and equipment.


  • Shells are tan or olive-green with distinct reddish-brown bands circling the shell. This feature is obvious in empty shells, but more subtle on living snails. 
  • 4-5 whorls with distinct sutures.
  • Operculum (trap door) present.
  • Adult snails can get up to  1 1/2 inches in length.
  • Banded mystery snail is often wider than the brown mystery snail

Ecology and Natural History:
The banded mystery snail is native to Georgia but has invaded farther north through the aquarium trade and purposeful introductions. It has invaded Ohio, Michigan, Wisconsin, Virginia, South Carolina, Pennsylvania, New Jersey, New York, New Hampshire, Maryland, Quebec, and the Great Lakes. It lives in lakes and slow-moving rivers. From spring to fall, the banded mystery snail lives in shallow water. In the fall, it moves to deeper water to overwinter away from the shore. Female banded mystery snails live 28 – 48 months while male banded mystery snails live 18 – 36 months. Females generally have between 4 – 81 young and can brood more than one batch of young at a time. Banded mystery snails feed on diatom clusters found on silt and mud substrates. It is a host to many parasites.

Oneida County Waterbodies with Banded Mystery Snails: Alva Lake, Big Stone Lake, Carrol Lake, Dog Lake, Fifth Lake, Hancock Lake, Horsehead Lake, Johnson Lake, Julia Lake, Katherine Lake, Little Bearskin Lake, Lone Stone Lake, Madeline Lake, Manson Lake, Maple Lake, Mid Lake, Minocqua Lake, Mud Lake, North Nokomis Lake, Pelican Lake, Pickerel Lake, Rainbow Flowage, Rice Creek, Squash Lake, Thunder Lake, Tomahawk Lake, Tomahawk River, Two Sisters Lake, Willow Flowage, and the Wisconsin River. 

Do you think your lake has banded mystery snails? Contact us to schedule a visit to your lake for confirmation.