Japanese Trapdoor Snails and Betta Fish

Japanese Trapdoor snails can be a great addition to your betta tank.

I am a biologist, and I’d love to share some tips about caring for Japanese Trapdoor snails in aquariums.

Cipangopaludina japonica by Judy Gallagher (CC BY 2.0)

Key Takeaways

  • Japanese Trapdoor Snails are also known as Japanese Mystery Snails and are native to East Asia.
  • They can survive in water temperatures between 39°F and 86°F but prefer temperatures around 68°F.
  • Japanese Trapdoor Snails have a long lifespan of up to 10 years in a suitable environment.
  • These snails are highly invasive and should never be released into the wild.
  • They are peaceful animals and nocturnal, spending most of the day hidden among decorations or even slightly buried in the substrate.
  • Japanese Trapdoor Snails are efficient at eating soft algae, but they’re not efficient at controlling large algal blooms.
  • They’re easy to keep in aquariums and prefer fine gravel or sand substrate to burrow.
  • Japanese Trapdoor Snails feed on detritus and silt, which are rich in biofilms, bacteria, and other organisms.

Japanese Trapdoor Snail Natural Habitat And Origin

Japanese trapdoor snails, also called Japanese mystery snails, are native to East Asia, specifically Japan and China, where they dwell in freshwater habitats like rivers, ponds, streams, and swamps. They are widely bred for food and hobby aquariums.

Adaptability and Life span

They can live in water between 39°F and 86°F  (4℃ and 30℃) but prefer temperatures around 68°F (20℃).
They are highly adaptable and found in diverse environments. 

Japanese trapdoor snails can survive in extreme environmental conditions, like environments lacking water. They bury themselves in the soil and wait until the water returns. 

They have a relatively long lifespan of up to 10 years in a suitable environment.

Invasive Species

These snails are highly invasive, competing with native species for resources, becoming a pest in lakes and rivers. Please never release Japanese trapdoor snails, or other pet snails, into the wild.

Japanese Trapdoor Snail Taxonomy

Japanese trapdoor snails are gastropod mollusks, which means they are members of the snails and snails group.

They have a single shell that grows over time and a distinctive head with two tentacles. They have a radula, a kind of toothed tongue used to scrape food.

The Japanese trapdoor snails belong to the Viviparidae family and the genus Cipangopaludina of the species Cipangopaludina japonica. They are named “trapdoor” because they have a door at the entrance to their shell that they can close for protection.

There are several species of Cipangopaludina, including Cipangopaludina chinensis (Chinese trapdoor snail). Although they are very similar in appearance, there are subtle differences that allow them to identify.

One of the most notable differences is the shape of the shell. Some species, such as Cipangopaludina chinensis, have a more rounded, pointed shell, while others, such as Cipangopaludina japonica, have a more elongated shell with a wider opening. In addition, the species also have different color patterns on their shells, which can help with identification.

Cipangopaludina chinensis by Peterwchen (CC BY-SA 4.0)

Another crucial difference is size. Cipangopaludina japonica is the largest of the species, reaching up to 7 cm in length, while Cipangopaludina chinensis is the smallest, generally not exceeding 2 cm.

For the hobbyist, Cipangopaludina japonica is the most common species. It is prized for its ability to help maintain aquarium water quality as it feeds on food scraps and other detritus. In addition, it is a very resistant species and easy to care for.

How Do Japanese Trapdoor Snails Behave?

Japanese trapdoor snails are peaceful animals, making them great for community aquariums. 

These snails are nocturnal, spending most of the day hidden among decorations or even slightly buried in the substrate.  At night, they spend most of their time looking for food. 

They’re good algae eaters but inefficient at controlling large algal blooms. They prefer the soft part of algae on rocks or glass.

Japanese trapdoor snails may leave the tank, especially if water conditions are less than ideal. 

They can close their shell door (like a trap) when they feel threatened. 


They can also survive long periods without food or water, making them well-adapted to live in unstable, hostile environments.

How To Set Up Your Tank For Japanese Trapdoor Snail

Japanese trapdoor snails are hardy creatures and easy to keep in aquariums


Japanese trapdoor snails eat soft algae, so it’s good to have adequate surface area for the algae to grow, like live plants and other decorations in your tank. 

Some good plant options include Cabomba, Anubias, and Java Moss

Plants can also help keep the water in good condition and provide hiding places.


A fine gravel or sand substrate is ideal. These snails like to burrow, and fine substrates allow them to do that. Gravel also allows the plants to grow well without impacting their roots (as sometimes happens with sand), helping to maintain good water quality.

Water parameters

Maintain the water at a pH between 7.0 and 8.0 and a temperature between 64°F and 75°F (C 18°C and 24°C).
Monitor the ammonia and nitrite levels carefully, keeping them as low as possible.

Other considerations

Japanese trapdoor snails are nocturnal animals. Ensure the tank has soft, diffused light, or even better, at night, switch off the lights. 

Ensure your tank lid is secure and securely closed to prevent snails from coming out.

Japanese Trapdoor Snail Diet

Japanese trapdoor snails feed on detritus and silt, which are rich in biofilms, bacteria, and other organisms. 

In nature, snails are a vital component of the aquatic ecosystem, as they reduce the accumulation of organic waste.

In captivity, Japanese trapdoor snails may occasionally feed on live plants. Generally, they’ll only eat softer parts of live plants and smaller animals when they get insufficient food.

A nutrient-poor diet can result in health problems like low immunity, scab formation, and disease.

It’s best to offer Japanese trapdoor snails a variety of foods, including algae and commercial food, and to allow them to feed naturally on detritus and biofilms in the tank. 

How Do Japanese Trapdoor Snails Reproduce In A Fish Tank? Can They Cause Snail Overpopulation?

Japanese Trapdoor Snails are not hermaphrodites and have a slow reproduction rate in aquariums. Although they can become pests in tanks, they don’t overpopulate as quickly as other snail species.

Because Japanese Trapdoor Snails don’t reproduce with the speed and intensity of many other snail species.

They are ovoviviparous. That means they don’t lay eggs, but the female “gives birth” to fully-formed young snails. Females can carry up to 120 eggs.

If needed, you can manually remove young snails

Japanese Trapdoor Snail Compatibility With Betta Fish

Japanese Trapdoor Snails are an excellent addition to a Betta‘s tank. These snails are peaceful and won’t bother the Betta. 

However, Bettas may try to eat snails if they’re hungry, so please feed your Betta properly.

Compatibility with other fish

Avoid predatory fish at all costs. Snails are easy prey for fish like arowanas and loaches.

It’s good practice to observe the behavior of the fish and the snails in the tank, ensuring everyone is fine. 

Where Or How Do You Get Them?

Many online vendors and local aquarium stores sell Japanese trapdoor snails. You should always look for healthy-looking animals with whole shells and ensure they aren’t missing any eyes or tentacles.

You can also buy from private breeders, but that can be a bit of a lucky draw as quality may vary.

Before purchasing, ensure you’re allowed to keep these snails in your area, as some regions have laws restricting the ownership of potentially invasive species.


Japanese trapdoor snails are a valuable addition to virtually any pond or aquarium. Aquarists love them for their peaceful temperament and ability to keep tanks and ponds clean.

Remember that these snails reproduce slowly in aquariums, but they can still become a pest if not adequately monitored. Due to their peaceful temperament, slow reproductive rate, and great cleaning abilities, these snails are an excellent addition to your Betta tank!

About the author

Hi, I am Marcelo.

I am fascinated with researching and writing about fish.
I have a degree in biology (herpetologist) and animal science (zootechnics) specializing in ornamental fish and South American biotopes.

You can find the articles I wrote here.

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