Chinese Trapdoor Snail

Looks how to spot one

Conical shell with trapdoor operculum

A sturdy, cone-shaped shell with six to seven smoothly rounded whorls, roughly 4 cm tall and 3 cm wide in a typical adult. A hard oval 'trapdoor' on the foot closes the shell opening when the snail withdraws.1

Personality what they are like

A calm, slow grazer that spends its time on soft bottoms browsing algae and debris.1

Daily activity how busy a day looks

Low activity needs; grazes steadily and rests or hibernates when the water turns too cold or too hot.1

Grooming and care the hands-on bits

Low maintenance, but because of its invasive-species status in some regions it must never be released into the wild, and in the EU it may not be kept or bred.1

Home where they are happiest

Soft-bottomed still or slow fresh water such as ponds and lakes. Grows best at about 20 to 28 °C and goes dormant below roughly 10 to 15 °C or above 30 °C.1

Food basics what goes in the bowl

An unfussy grazer of bottom material and algae; diatoms are an especially good food.1

Company who they like around

Unlike many snails it has separate sexes, so a male and a female are needed for breeding.1

The story where it all began

Eaten in China since prehistoric times, as shells from Neolithic sites show. It reached San Francisco's Asian food markets in the late 1800s and from there spread through many North American waters.1

Recognised by the official bits

Taxonomy

Now placed by Wikipedia under Margarya chinensis; long known as Cipangopaludina chinensis.1

Legal note

Listed by the EU as an invasive alien species of Union concern, which bans import, breeding, transport and release there; release is also illegal in some US states such as Minnesota. Check local rules before keeping it.1