Chinese mystery snail
Chinese mystery snail (Cipangopaludina chinensis) is a large, invasive freshwater snail native to Southeast Asia and eastern Russia. It has been introduced to other regions through the aquarium trade and food markets. Once established, it can outcompete native molluscs, alter ecosystems, and degrade water quality.
Chinese mystery snails are not currently in Australia but pose a serious biosecurity risk. The invasive species has been introduced to North America where it was first recorded in 1905. It is especially widespread in Ontario, Canada.
Reporting
If you think you have seen a Chinese mystery snail in NSW, please take several clear, high-resolution photos of the shell. For identification, we need to see the:
- Shell size – please include something for reference (e.g. a coin, ruler)
- Shell shape and colour
- Close-up of the shell opening and operculum (lid-like structure).
Please send photos to aquatic.biosecurity@dpird.nsw.gov.au, along with details of when and where the snail was seen.
Identification
Key features
- The shell is smooth and somewhat spherical, thin walled but strong
- General length of 40mm but up to 65mm with a large oval opening
- Colour varies from olive green to brown
- Distinct dark lines separating the 6-7 whorls
Known locations
- Not in Australia
Habitat
- Found in freshwater lakes, ponds, and slow-moving rivers
- Prefers mud, sand, or silt substrates
- Often on aquatic plants or buried in sediment at a depth of 3m or less
- Tolerates a wide range of water temperatures (0-45°C)
Vectors
- Illegal release from aquarium and aquatic plant trade
- Illegal release from live food trade
- Contaminated boats or trailers
Impacts
- Outcompetes native species for food and space
- Alters water quality
- Fouling of pipelines, particularly inlets and outlets
- Increase in maintenance costs
Similar native species
These native species may be confused with the Chinese mystery snail. These species do not need to be reported to biosecurity.
Billabong banded snail (Notopala kingi suprafasciata) (critically endangered)
Key features
- Outer shell is often polished and spherical, green to brown in colour
- Up to 32mm in size
- Lacks dark lines between the 5 whorls, but has bands diffused along shell circumference
Known locations
- Large ponds and billabongs throughout western New South Wales
Habitat
- Muddy sediment within waterbodies
Hanley’s river snail (Notopala hanleyi) (critically endangered)
Key features
- Outer shell is smooth and spherical, green to brown in colour
- Maximum width of 25mm
- Lacks dark lines between the 5 whorls
Known locations
- Murray River catchment, Lachlan and Murrumbidgee Rivers included
Habitat
- Attached to logs or rocks, or in sediment along riverbanks
- Artificial irrigation pipeline environments
Darling river snail (Notopala sublineata) (critically endangered)
Key features
- Outer shell is smooth and spherical, green to brown in colour
- Maximum width of 25mm
- Lacks dark lines between the 5 whorls
Known locations
- Formerly Darling River and associated tributaries, now restricted to irrigation pipes near Bourke, Brewarrina, and Walgett.
Habitat
- Attached to logs or rocks, or in sediment along riverbanks
- Artificial irrigation pipeline environments