Japanese Trapdoor Snail: Underrated Water Cleaners

Japanese Trapdoor Snail Infographic

Japanese trapdoor snails, also known by their scientific names Vivparus malleattus or Cipangopaludina malleata are a freshwater snail species that is highly sought-after amongst aquarium hobbyists. Often added to tanks as part of the janitorial team, it’s been reported that this gastropod could help increase the quality of the water in the tank.

Shall we take a closer look at how, and why?

Why Does the Japanese Trapdoor Snail Have Two Scientific Names?

We might as well get this question out the way nice and early. It’s quite common for snails to have more than one ‘nickname’, or name that we use instead of the complicated scientific one. It’s very rare for an animal to have two scientific names, though.

Japanese trapdoor snails were originally known as Vivparus malleattus, but the name was changed when scientists learned a little more about them and realised, they needed to be moved to a slightly different family.

These days, Japanese trapdoor snails are known as Cipangopaludina malleata. There are reported to be four other snails in the ‘trapdoor’ group.

To make things even more complicated (thanks, science-folk!), this is a very similar name to another snails, such as Chinese mystery snails – Cipangopaludina chinensis. Japanese trapdoor snails and their Chinese cousin are not the same snail, however. Make sure that you do not confuse the two.

What Do Japanese Trapdoor Snails Look Like?

The Japanese trapdoor snail has a very spiral-shaped shell, and it gets thinner towards the top and is wider at the base, where it meets the snail. This is especially the case when you compare it to the garden snail (land snail), which is very rounded. The trapdoor snail shell actually looks as though it has been sculpted or hammered into shape, too perfect to be created by nature.

That’s actually how it got the name ‘malleattus‘ – it literally means beaten or hammered in Latin. The snail looks as though it has been hand-beaten into shape by a master artist!

The shell itself can come in a range of colours, including light brown, dark brown, reddish brown, olive green, dark green, and a mixture of everything in between. It can be darker at the bottom and lighter at the top, which is often the case older snails.

You can even get off-white/cream-colored trapdoor snails, but they are considered to be quite rare. (And, therefore, usually much more expensive to buy.)

How Big Do Japanese Trapdoor Snails Get?

Many people are surprised to learn that Japanese trapdoor snails grow to just under 2 inches in length. They certainly look a whole lot bigger, especially in pictures on the internet.

If you wanted to know how tall these little pond snails were, they’re about as high as they are long – 2 inches.

For some comparison, Chinese mystery snails usually grow to around 1.5 inches in length, and nerite snails are even smaller – 1 inch.

Japanese Trapdoor Snails Lifespan

Although the habitat and other environmental factors, such as water temperature and other water parameters, will play a massive part in the life expectancy of any snails, most Japanese trapdoor snails live for between 5 and 10 years.

If you keep up with good Japanese trapdoor snail care, you can reach the top end of that scale. Those in an outdoor pond are generally considered to have shorter lifespans than those kept in well-maintained aquariums.

Where Will You Find Japanese Trapdoor Snails?

The clue is in the name with this one… kind-of.

These freshwater snails originated in Japan (as you might’ve guessed) but it has since gone on to pretty much conquer the Western coastal parts of America, heading into the Pacific. In fact, these days, you can find these pond snails in many, many places around the world. It’s on a (slow) path to world domination!

Japanese Trapdoor Snail Habitat Information

This omnivorous snail prefers murkier bodies of fresh water, decorated with plenty of aquatic plants. Murky water usually indicates that it is full of something, such as organic material, waste material, and vegetation. All these things provide nutrition to a Japanese trapdoor snail.

Having a preference for murky, muddy water doesn’t mean you won’t find this gastropod in clear, clean water, however.  

What Does the Japanese Trapdoor Snail Eat?             

One of the reasons why Japanese trapdoor snails are so popular among freshwater aquariums and their enthusiastic owners is because they are super-efficient waste and algae eaters. They love the stuff!

This snail is omnivorous, which means it will eat both plant material and animal matter, but it’s not going to go on the hunt for smaller critters to kill. Instead, it moves around the tank, slithering all over the glass, plants, and ornaments, cleaning away algae and other materials.

That’s why people want it in their tanks: the shelly-dudes do the clean-up work, so you don’t have to! (Sort-of.)

This species is not choosy in the slightest when it comes to feeding time. They will eat things that other tank mates won’t, including:

  • Fish poop

  • Algae

  • Uneaten fish food

  • Decomposing biological matter (such as dead fish)

  • Decaying plant life

They usually do not eat live plants in a tank. Your aquatic blooms will be fine!

What Eats Japanese Trapdoor Snails?

Any species that eats snails, will eat Japanese trapdoor snails. The following list of fish would make terrible tank mates:

  • Catfish

  • Gourami

  • Loach

  • Killifish

  • Tetra

  • Danio

  • Barb

If you are putting this snail species in a freshwater tank, take a few moments to check whether or not they will be compatible with the other tank mates first. If you don’t, you might find that your snail is killed within just a few hours of being in its new habitat.

You will also want to avoid putting Japanese trapdoor snails and assassin snails together. It will not be a match made in heaven!

Are Japanese Trapdoor Snails Asexual?

No, Japanese trapdoor snails are not asexual. Unlike other species, this snail needs a male and a female to come together and breed before fertilisation, pregnancy, and birthing. This is the same as mystery snails, nerite snails, and many other freshwater snails.

Malaysian trumpet snails, on the other hand, are an asexual freshwater species.

Fewer snails are asexual than you might have thought!

Do Japanese Trapdoor Snails Lay Eggs?

No, Japanese trapdoor snails do not lay eggs. They are live-bearing snails, which means they give birth to baby snails.

How Often Do Japanese Trapdoor Snails Reproduce?

Japanese trapdoor snails reach sexual maturity once they reach around 2 years of age. Some will start reproducing a little earlier – around 18 months of age.

Females are pregnant for the same length of time as a female human – approximately 9 months. At that point, she will give birth to around 15 to 25 young, although 15 to 20 seems to be the average. Not all of those will survive, of course, but if your freshwater habitat has ideal conditions, with few predators, most of them probably will.

Do Japanese Trapdoor Snails Burrow?

It is not common for these snails to burrow. They might disappear into their shells for a couple of days or sit motionless for a while before kicking back into life again, but if you have lost your gastropod(s) in the tank, there’s a higher chance they will have escaped than burrowed into the substrate.

Overall, this species is pretty active. It can cover some serious ground, looking for food on the substrate and live plants, once it gets going. Obviously, it won’t ever be as fast as most of your other pets, but it can still get going when it wants to.

Are Japanese Trapdoor Snails Aggressive?

No, this is not an aggressive snail. In fact, it is one of the calmest and most peaceful.

This snail will get along with most other freshwater fish and snails. Obviously, pairing them up with a snail-eating fish isn’t a good idea. These include catfish, koi, and goldfish, to name but a few.

You should avoid putting Japanese trapdoor snails and assassin snails in the same tank or aquarium, too. The two are likely to fight… to the death.

What Can the Japanese Trapdoor Snail Live With?

You’ll be happy to know that you can safely add a wide variety of tank mates. in with your trapdoor snails. These include:

  • Blue velvet shrimp

  • Bee shrimp

  • Sakura red cherry shrimp

  • Other snails (freshwater, apart from assassin snails)

  • Freshwater/aquarium fish (apart from those listed above)

Keeping Japanese Trapdoor Snails: Final Tips & Tricks

If you are dipping your toes into the aquarium hobby world and are thinking of getting Japanese trapdoor snails to add to yours, here are a few final things you should probably know:

1 – You will probably need to feed your snails a little bit.

Although this snail will be more than happy munching through the fish poop, uneaten food flakes, naturally occurring algae, and other tank waste, you may need to add a little extra food. This is more so if you have multiple trapdoor snails.

The Japanese trapdoor snail will eat:

2 – Younger trapdoor snails are lighter in color.

Juvenile Japanese trapdoor snails are not only tiny, they’re also almost see-through to start with. When they do start to gain the color, it stays relatively lighter at first. As the snail ages, the shell becomes darker.

3: You’ll need -this size- tank for keeping Japanese trapdoor snails:

Japanese trapdoor snails do like to move around, so you should aim to give them at least a 10-gallon tank or aquarium. The more snails you want to add, the more gallons you’ll need.

4: These are the correct Japanese trapdoor snails water parameters:

Gastropods are very sensitive to changes in water, and incorrect water parameters. They need water that is between 69F (20.5C) to 88F (31C).

You will also need to ensure (and test) the acidity of the water (pH level). It should be between 6.5 and 8.

And finally, when it comes to the hardness of the water, trapdoor snails tend to do best in water that is soft-medium hardness.

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