Japanese Trapdoor Snail
Cipangopaludina japonica
A hardy, coldwater-tolerant snail that grazes algae and is great for ponds too.
| Difficulty | Beginner |
| Min. Tank Size | 40 L |
| Temperature | 10.0–28.0 °C |
| pH Range | 6.5–8.0 |
| Max Size | 6.0 cm |
| Lifespan | 3-5 years |
| Diet | Omnivore |
| Temperament | Peaceful |
Overview
The Japanese Trapdoor Snail (Cipangopaludina japonica) is a hardy, coldwater-tolerant snail that grazes algae and is great for ponds too. It reaches about 6 cm and can live for roughly 3-5 years with good care.
This guide covers everything in plain language: tank size and setup, water parameters, the best foods (with recommended brands), which shrimp and tank mates it can safely live with, breeding, and the common problems to avoid. It is rated Beginner to keep.
Natural Habitat & Origin
Aquarium snails are peaceful grazers that clean algae, biofilm and leftover food. They are sensitive to copper and need enough calcium (hardness) in the water to build strong shells.
Tank Size & Setup
Provide at least 40 litres. Give it space, hides and a secure setup suited to its size and habits.
They need little beyond a stable, cycled tank with some algae and biofilm to graze, plus enough calcium in the water for shell growth.
Always add invertebrates only to a fully cycled, mature tank - they are far more sensitive to ammonia and nitrite than most fish.
Water Parameters
Keep the Japanese Trapdoor Snail at 10-28 °C with a pH of 6.5-8.0, in moderately hard water (GH 6-15); they are happy in most Australian tap water once it is dechlorinated and stable.
Stability is everything for invertebrates: test regularly, keep ammonia and nitrite at zero and nitrate low, drip-acclimate new arrivals slowly over an hour, and make only small, steady water changes. Remember that copper - found in some fish medicines and plant fertilisers - is lethal, so always check labels.
Diet & Feeding
The Japanese Trapdoor Snail is a omnivore. In Australia, good options include the algae and biofilm in the tank, topped up with Hikari Algae Wafers and blanched vegetables; add a calcium source (cuttlebone) for strong shells.
Feed lightly - invertebrates get much of their food from natural biofilm and algae, and overfeeding quickly fouls the water and triggers losses. A little, a few times a week, is plenty for most shrimp and snails.
Which Shrimp & Tank Mates Can Live Together?
This snail is completely peaceful and safe with shrimp, fish and (with the noted exceptions) plants. Nerite and black devil snails cannot breed in freshwater, so they never overrun a tank; bladder, ramshorn and trumpet snails can multiply quickly if you overfeed. Assassin snails will eat other snails, so don't mix them with snails you want to keep. Giant/Colombian ramshorns and rabbit snails may nibble soft plants.
Breeding
Nerite and black devil snails cannot breed in freshwater (their larvae need brackish water), so they will never overrun your tank. Mystery, ramshorn, trumpet and bladder snails breed readily in freshwater - control their numbers simply by feeding less.
Common Problems & Care Tips
The main care points are calcium for a strong shell (soft or acidic water causes pitted, eroding shells), avoiding copper, and not relying on the snail to survive on algae alone in a clean tank.
Quarantine and acclimate all new livestock carefully, and watch daily for sluggishness, failure to eat or trouble moulting.
Is the Japanese Trapdoor Snail Right for You?
The Japanese Trapdoor Snail suits beginners and experts alike, as long as you can provide 40+ litres, the right water, copper-free conditions and suitable tank mates.
Get the basics right and these fascinating invertebrates are some of the most rewarding animals in the hobby. Use our aquarium tools to plan your setup and browse our fish and plant guides for safe tank mates.