Japanese trapdoor snail (Cipangopaludina japonica) care guide

Group
Snails
Other names
Heterogen japonica, Japanese mystery snail, Paludina japonica, Viviparus japonicus, Bellamya japonica, Vivipara sclateri
Family
Viviparidae
Origin
Japan, Korea and Taiwan: lakes, ponds, slow rivers and rice paddies
Water
freshwater
Care level
beginner

Care

The Japanese trapdoor snail is a large freshwater snail with a globe-shaped brown to tan shell of seven to eight whorls, which darkens with age; young snails have fine hairs on the shell skin. It closes its shell with a tight operculum (the 'trapdoor'). Its accepted name is now Heterogen japonica; Cipangopaludina japonica is an older name still used in the trade. It is easily confused with the Chinese mystery snail (Cipangopaludina chinensis). It lives in lakes, ponds and slow rivers over sandy or muddy bottoms with dense plants. In the hobby it is kept in coldwater tanks and ponds and is popular as a pond algae and detritus eater; it is generally reported to tolerate cold winters. Our sources have little on this species; the figures are general guidance, not from a source. Our sources give no water figures for this species. It has become invasive in North America, where it competes with native snails, changes nutrient balance and algae in the water, and can build up large populations. Never release this animal or empty its tank water into drains or waterways. Think carefully before putting it in an outdoor pond, from which it could escape. Copper: copper-based medicines and some plant fertilisers are toxic to shrimp, snails and most other invertebrates. Never dose them in a tank holding this animal, and check the label of any treatment or fertiliser before use. Sources: Wikipedia (en.wikipedia.org/wiki/Heterogenjaponica). Checked October 2026.

Diet

Grazes bacterial film, detritus, algae and decaying plant matter. Supplement with sinking pellets, algae wafers and blanched vegetables in a tank; ponds usually supply enough food.

Breeding

Like other Viviparidae it has separate sexes and gives birth to live young: there are no egg clutches, and fully formed baby snails appear a few at a time. It breeds slowly and steadily rather than in plague numbers. Our sources do not describe its breeding in detail.

Compatibility and tank mates

Peaceful; safe with fish, shrimp and most plants. In the wild it is eaten by crayfish, catfish and birds; keep it away from large crayfish, loaches and puffers.

Last updated 8 October 2026. Community-edited care guide on Aquatic-Auctions.

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