Japanese Trapdoor Snail 101: Care, Size, Breeding & More

The Japanese Trapdoor Snail is a freshwater species that doesn’t get enough attention. Not only are they pretty and low-maintenance, but they bring a number of benefits to your tank.

These little critters will snack on algae and organic matter to help keep your tank nice and clean. You’ll definitely notice a difference in the quality of your water with a few of these snails (depending on the size of your aquarium of course).

Since we’re such a big fan of this species we wanted to put together a full care guide for them. Reading it will give you a bunch of useful information about the benefits Japanese Trapdoor Snails can bring, and how to keep them healthy.

Species Summary

As you probably guessed from the name, the Japanese Trapdoor Snail (Viviparus malleattus) can primarily be found in Japan. While this is where the largest concentration of this species is located, they’re actually found all over the world at this point.

You can typically find this species hunkered down in murky waters where there’s a lot of mud. These areas are usually full of plant life that help facilitate organic matter buildup for them to eat.

They’re not only scavengers but some of the best algae eaters around. Japanese Trapdoor Snails will spend a significant amount of their time searching for algae to munch on in the wild, and in your aquarium. They don’t eat living plants though!

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This species lacks the siphon that you’ll find on some of the other popular aquarium snails. They can also live in extremely cold temperatures (which is partly why they’re found in so many different regions around the world).

Author Note: It’s important to check with the laws in your state to see if they allow Japanese Trapdoor Snails as pets. There are certain areas where this species is considered invasive and as a result, can’t be kept in captivity.


The average lifespan of Japanese Trapdoor Snails can range from 5 to 10 years. This is quite an impressive length of time!

If you want to make sure these creatures live as long as possible you’ll need to provide the best care possible. In all the instances where these snails have reached the upper limits of their lifespan, they’ve been kept in a stellar habitat.

Great water quality and a great diet are the two most important factors.


The appearance of Japanese Trapdoor Snails can vary quite a bit depending on the specimen. At their core, these snails have a very beautiful natural look that many aquarists enjoy.

Shell color is the area where you’ll notice the most variation. You’ll see green, brown, black, and even some cream. The most common colors are green and brown (with brown being the dominant color).

There will usually be a base color on the largest whorl and some different colored rings and textured lines that extend further up. It’s not uncommon for the base color of the shell to get lighter and lighter the higher up it goes.

Just like other snails, they have an operculum which serves as a trapdoor to protect them when needed. All they need to do is tuck inside and pull it over the opening of their shell!

It’s common for Japanese Trapdoor Snails to have three whorls, but sometimes you’ll see a specimen with a different count (usually more). Their shell tapers off and gets significantly thinner the further it is from their body.

Average Size

The average Japanese Trapdoor Snails size is around 2 inches. While there are instances where this species has exceeded this, it’s quite rare.

There are a number of factors that influence the size of this species. The main ones are water quality, diet, and how well they were raised or bred before you got them.

Japanese Trapdoor Snail Care

Japanese Trapdoor Snail care is pretty darn easy. Like most snails, this species is extremely low-maintenance and won’t require any special attention.

These are small and hardy animals which makes them very forgiving to the kind of conditions in the tank. You’ll spend significantly more time paying attention to their tank mates!

With that being said, you shouldn’t fall into the trap of thinking that Japanese Trapdoor Snails can survive no matter what conditions they’re kept in. Although they’re quite hardy, there are still clear parameters that suite them best!

This section will go over the core elements of setting up their tank and habitat. If you stick to the following recommendations, your snails will be quite happy.

Tank Size

The ideal tank size for Japanese Trapdoor Snails is a minimum of 10 gallons. These are small creatures that don’t need much room to thrive!

However, if you can give them a larger tank it’s never a bad thing. More space allows you to set up a habitat with more variety, or keep additional snails.

Obviously, if you plan on keeping the Trapdoor Snail with freshwater fish you’ll need to be aware of the tank size requirements that they have as well. Plan around the larger animals!

Water Parameters

You have a lot of wiggle room when it comes to water parameters. In fact, it’s one of the easiest parts of Japanese Trapdoor Snail care!

Their hardy nature and ability to live in various climates means you can be a bit flexible and plan water parameters around their tank mates. Below are the ideal parameter ranges you should provide.

  • Water temperature: 68°F to 85°F (somewhere in the middle is ideal)
  • pH levels: 6.5 to 8
  • Water hardness: Soft – Medium

Author Note: It’s a good idea to perform regular tests especially after you’ve introduced them to a new tank. Sudden changes can cause stress to these snails and potentially cause health complications. Once they’re stable you can check less-frequently.

How To Set Up Their Habitat

Creating a great habitat for these snails is quite straightforward. This is not only convenient for you during the setup process, but allows them to be kept with a variety of tank mates.

We always like to start with the substrate.

Japanese Trapdoor Snails do best with a soft and sandy substrate. This is because they’ll spend a lot of their time moving along the bottom of the tank, and a rough substrate can cause irritation (and possibly infection).

Next up is plants. Since these critters love to snack on organic plant matter and algae, it’s only natural that they’ll do best in a well-planted tank.

The neat thing is that these snails won’t actually eat your living plants (unless they’re extremely hungry). They’ll wait for bits and pieces to fall before snacking. That gives you a lot of flexibility with the kind of plants you can keep them with!

Other smart items to include in their tank are rocks and pieces of wood. These make great surfaces for many types of algae to grow which this species will appreciate. If you’re keeping them in a smaller tank you might not have the luxury of adding these since you don’t want the aquarium to become too cramped.

Author Note: It’s a smart idea to cover your filter intake as well as put a lid on the top of the aquarium. Japanese Trapdoor Snails can easily get sucked up or fall out if they wander too far.

While this doesn’t happen often, all it takes is one adventurous moment for your snail to get in trouble.

Common Possible Diseases

The nice thing about this species is that they’re fairly resistant to disease. With that being said, there are some diseases you’ll want to look out for.

Oedema is a common occurrence in older snails that causes them to build up too much fluid in their tissue. This will lead to swelling and serious health complications if it progresses. If this happens to your snail there’s not a whole lot you can do other than wait to see if their condition improves.

There are some other less common illnesses and infections you’ll want to look out for as well. Keep an eye out for any strange behavior or visible signs of illness.

One of the most important things to remember when caring for Japanese Trapdoor Snails is that copper is extremely toxic to them. Even the smallest traces of copper in their water can be fatal.

The reason it’s important to know this is because many medications that you would include in their water contain copper. That means if you need to treat another fish in your tank, you could accidentally be poisoning your snails.

Food & Diet

One of the convenient things about this species is that their diet is very straightforward. These snails are omnivores and scavengers who will snack on just about any organic matter they can find!

Being able to facilitate some algae growth in your tank is ideal. These animals are constantly looking for biofilm and algae to snack on! If you follow our tank setup recommendations this shouldn’t be a problem.

You’ll also want to give them some plant-based pellets or bottom feeder tablets as well. You shouldn’t rely on natural algae growth as their only source of food.

Most aquarists like to mix up their diet a little bit by feeding them some blanched veggies as well. Zucchini, lettuce, cucumbers, and kale are all great choices!

Author Note: Don’t make the common mistake of thinking you can put in a ton of food and still rely on these snails to keep the tank clean. If you overfeed them, uneaten food will negatively impact the water quality.

Behavior & Temperament

Japanese Trapdoor Snails are a peaceful and fun species to watch. They will spend their time exploring the tank looking for things to snack on, and won’t cause trouble.

If you’re keeping them in a community tank they’ll simply mind their own business and leave the other creatures alone. Their behavior when they’re by themselves and when they’re kept with others is quite similar.

Contrary to popular belief, these snails are actually quite active (this is more noticeable at night). Many people assume that they sit around all day, but that simply isn’t the case. You’ll be surprised by the amount of ground they cover on a daily basis!

Every once in a while you’ll see them camp out in their shell and not move for a while. Most of the time this isn’t a sign of illness, it’s just something they do.

You’ll sometimes see these snails make a run for the top of your aquarium. While this isn’t a common occurrence, it happens enough that you should always keep a lid on your tank.

Tank Mates

Because of their peaceful and hardy nature, there are a number of tank mates you can choose for Japanese Trapdoor Snails. Honestly, the only thing you need to worry about is keeping them with a creature that wants to eat them!

You can keep them with most other freshwater aquarium snail species (except the Assassin Snail) if you want some variety. Shrimp are also a great choice as well. Cherry Shrimp, Ghost Shrimp, Amano Shrimp, and Bamboo Shrimp are our favorites.

When it comes to fish you’ll want to be a little more careful. There are many freshwater species that view snails as food which is obviously something you need to avoid.

Here are some good options to consider:

This is just a quick list to get you started. There are plenty of other viable tank mates you can try!

Author Note: We know some owners have had success keeping their Japanese Trapdoor Snails with small cichlids like the Bolivian Ram or Apistogramma. Feel free to give this a shot, but be aware that there’s a little bit more risk with these.

Japanese Trapdoor Snail Breeding

Breeding Japanese Trapdoor Snails is a very simple process. In fact, there’s not much you need to do! As long as you’re keeping some males and females in a well-maintained tank with optimal water parameters, they should do the rest.

The nice thing about this species is they won’t take over your tank. Some freshwater snails can reproduce quite fast and lead to overpopulation, but that’s not the case with the Trapdoor!

This allows you to easily breed or limit the number of snails you want based on your preferences. It doesn’t get much easier than that.

Keep in mind that the Japanese Trapdoor Snail reproduction process can’t occur until the snails are at least a year old. Knowing this will help you plan out your overall breeding strategy.

Wrapping Up

As you can probably tell, Japanese Trapdoor Snail care is something that anyone can manage. It doesn’t matter if you’re a brand-new aquarist who wants something easy or an experienced veteran who doesn’t want the hassle, this snail is a great choice.

The nice thing about this species is how low risk they are to try. They don’t need a large tank, can be kept with a ton of other creatures, and won’t take up a lot of your time.

There’s no reason not to give them a chance!

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