Armour Township says that there has been a “potential sighting” of an invasive freshwater aquatic snail species in local waterways.
The Chinese Mystery Snail (Cipangopaludina chinensis) is native to Southeast Asia and eastern Russia and is believed to have been introduced into North America during the late 1800s as an addition to the Asian food market and aquarium trade.
According to the Invasive Species Centre, The shells of Chinese mystery snails are thick and rounded and can reach lengths of 6 -7 cm. Most commonly, they are olive green in colour but can range from greenish brown to reddish brown. Their shells have 6-7 whorls, and an oblong shaped lid to protect them and deter predators. Females typically live longer than the males. Once mature, female Chinese Mystery Snails deliver fully formed and shelled offspring, born with 3–5 mm shell diameters. Throughout June to late October in their non-native North American range, these mature females reproduce numerous times, with just a single female capable of producing an average of 25-35 offspring per brood.
The snails have been sighted in several Canadian provinces, with Ontario having the highest reported number of sightings, making it most at risk of aquatic ecosystem degradation. In 2020, Ontario’s Invading Species Awareness Program confirmed that the snails were found in Huntsville. In 2021, invasive snails were removed by the thousands from Haliburton County lakes by a group of volunteers from the Invasive Species Awareness program, Coalition of Haliburton Property Owners’ Association, and the Ontario Federation of Anglers and Hunters. By 2024, the Mystery Snail Project reported collecting one million snails.
The most preferred habitat of the Chinese Mystery Snail includes lakes, rivers, and ponds, but sightings have also been reported in marshes, bays, ditches, and harbors. The large size, multiple feeding mechanisms, resistance to predation, and ability to withstand environmental stressors, allows the Chinese Mystery Snail to easily out-compete native freshwater gastropods and mollusks. This can decrease the population sizes of common mollusk food sources for predators such as otters, muskrats, waterfowl, and fishes. In addition, the snail alters nutrient cycling by excreting large amounts of fecal matter.
The snails also have the potential to be a vector for parasites and diseases and have been reported to clog water intake pipes. Their empty decaying shells can also wash up on shore and could create hazards if stepped on.
If Chinese Mystery Snails are spotted, if possible, they should be removed and disposed of far away from that waterbody, in a suitable compost or garbage bin. All watercraft and equipment should always be cleaned thoroughly after exiting any waterbody, and live wells and bilges drained on land. This ensures that boaters are not spreading aquatic invasive species such as the Chinese mystery snail from one waterbody to another.
If you think you’ve encountered an invasive species, take a photo, mark your location, and call the Invading Species Hotline at 1-800-563-7711, or report online at www.EDDMapS.org.
