Fact Sheet

Chinese Mystery Snail


Cipangopaludina chinensis | Other Names: Black Snail, Trapdoor Snail


Adult shells up to 70 mm long with 6-8 whorls. Juvenile shells are wider than long and may be spiraled with stiff hairs. Shells have an operculum (trap door) that can seal the shell and range from light to dark brown (nearly black). Adult female snails have two long, straight tentacles and males have one long, straight tentacle and one shorter, curved tentacle.

Habitat & Impact

In organic layers at the bottoms of freshwater lakes, rivers, and ponds. Tolerates temperatures from 0-45̊C. Resistant to predation and chemical elimination due to its operculum. Has apparent resistance to native parasites and may host parasites of water foul and those linked to human health. Females can birth up to 100 live young at a time, quickly overpopulating an area and outcompeting native molluscs for resources. May prey opportunistically upon native fish eggs, reducing survival rates, and may clog irrigation system intake pipes.


First introduced to the continent in the 1890s for the Asian food market. Can survive up to four weeks outside of water and thus has a high probability of spreading between bodies of water.

Length of Chinese Mystery Snail

Key Identification Features

Over 40 mm long, with 6 to 8 whorls, and brown or black shell.

Chinese Mystery Snail underwater
Chinese Mystery Snails washed up on shore

Interesting Fact

The mystery of Chinese Mystery Snail is the sudden appearance of their live young.

Stewardship Actions

If boating, swimming or fishing in areas with expected Chinese Mystery Snail exposure, clean your gear, avoid transferring water or organic material (including bait) from one water body to another, and never dump bait or an aquarium into any natural waterbody. If seen, please report to XMARinvasive@dfo-mpo.gc.ca or iNaturalist.