There are over 80 infestations of Chinese Mystery Snail in New Hampshire!
One of the main identification features of the mystery snails is their size. Adult snails are over 1 ½ inches in length (snail shell length is measured from the lip of the shell to the tip of the whorl). Shell color varies from olive green to brown to reddish brown. The shell has 6-7 whorls and no banding. They have an operculum (trapdoor), which seals off the snail from adverse water conditions.
Chinese Mystery Snails achieve very high densities and adversely affects aquatic food webs. It competes with native snails for food and habitat and may contribute to their decline. They may also transmit parasites and diseases. This species also clogs screens on any size water-intake pipe, making them an economic nuisance in addition to an ecological threat.