Black Mystery Snail: Size, Lifespan, Breeding, FAQs & More

Posted by Miles Harrison on 10/26/2022

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Black Mystery Snails are some of the easiest to care for in the hobby. These creatures are some of the hardiest, making them excellent invertebrates for beginners new to snail keeping. If you’re interested in caring for this species, we promise you won't be disappointed.

In this guide, we’re going to discuss all there is to know about keeping black mystery snails. We’ll discuss breeding, size, and lifespan, and we’ll even answer some of the most frequently asked questions about the species.

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Species Summary

Considered to be some of the most peaceful aquarium snails, Black Mysteries have distinct appearances and comical personalities. These snails are members of the Ampullariidae family, which comprises about 120 different species. Members of this family all share one distinct feature, they have a 2-inch siphon attached to their bodies that they use to consume and locate new food sources.

Native to South America, the West Indies, Southern United States, and Central America, these snails are quite widespread.

Hobbyists should be aware that these snails are different from invasive apple snails, which are illegal in the United States. Black Mystery snails will only grow to reach a few inches in length, and the shells of these snails can include a wide array of different patterns and colors.

These snails will stand out in an aquarium, as their black bodies are truly a sight to behold!

Image of a Black Mystery Snail
Adult Black Mystery Snails grow to reach about 1.5 inches in length


One of the most interesting parts about the appearance of black mystery snails is their distinct shells that vary from snail to snail. Black Mystery Snails can have shells that are jet black, gold, or completely white. Their bodies are mostly black but can be shades of gray as well.

Female Black Mystery Snails are typically larger than males, but it can be difficult to determine a gender difference. You’ll need to have raised two snails that are fed the same diet, in the same water conditions to determine which snail might be a male and which might be a female.

Their calcium-based shells have a traditional spiral pattern, and their eyes appear at the tips of their upper tentacles. It’s believed that these snails can see subtle differences in light, which they use to navigate around the aquarium surface. Black Mystery Snails also have two lower tentacles, which they use to feel for new potential food sources.

Interestingly, these snails also have a small respiratory system, and as such, are capable of living outside of the water. Don’t be surprised if you find your snail cruising around the glass above the waterline, where they will occasionally come up for air.

If threatened, the species will retreat into its shell, and although they may appear lifeless, after a short duration, they will emerge from their shells and continue to navigate around the aquarium.


Adult Black Mystery Snails should grow to reach about 1.5 inches in length. Store-bought black mystery snails are often sold as juveniles and are typically only a quarter of an inch in size.

As long as your black mystery snail has plenty of available food or algae to munch on, it should have no issues growing to reach its full size.

Black Mystery Snail Care

Caring for black mystery snails is as easy as it gets. There is not much you need to do to keep a healthy black mystery snail, but you should still be aware of its basic care requirements.

Black mystery snails are sensitive to high levels of ammonia and nitrate, and if you plan on keeping these in a freshwater aquarium that’s being injected with CO2, you’ll want to closely monitor the health of your black mystery snails.


Black Mystery Snails are relatively short-lived, and typically only live for about 1 year in captivity. Given proper water conditions, and a consistent food supply, they can live for slightly longer, but it’s safe to assume most will average one year.

Store-bought juvenile black mystery snails will typically be a few months of age at the time of purchase. Determining the snail's age at the time of purchase will give you a good idea of how long you can expect your black mystery snail to live.

Tank Size

One of the best parts about owning black mystery snails is that they can do well in almost any aquarium. Since adult black mystery snails can grow to be about 2 inches in length, we recommend an aquarium that’s at least 2.5 gallons in size.

Housing black mystery snails in tanks that are at least 2.5 gallons, guarantees that they’ll have plenty of room to explore, and since there is a large amount of surface area, there is a higher chance that small amounts of algae will form, giving the black mystery an additional food supply.

Water Parameters

Black Mystery Snails can be sensitive to changes in water chemistry, but one of the most important things to watch out for is copper. Exposing black mystery snails to dangerous levels of copper can be lethal! If your home has old, copper pipes, you’ll want to test your water supply with a copper test kit . If high levels of copper are detected, you may need to purchase an RO/DI unit to filter out the copper.

In general, try and maintain the following water conditions, which they will be quite happy with:

If you can manage to maintain the following water conditions, you should be in excellent shape.

Water Temperature: 68°F-84°F

pH: 7.8-8.4

KH: 12-18 DKH

GH: 8-18

Black Mystery Snails do best in hard water, so if you live in an urban environment, where tap water tends to be a bit on the hard side, you should have no problem keeping these snails. If you have well water, or your water is much softer, you can supplement your water supply with seachem equilibrium .

Tank Setup

Setting up an aquarium for black mystery snails is straightforward. We recommend starting with a gravel-based substrate, such as CaribSea’s eco-complete . This nutrient-rich substrate will promote plant and algae growth, but you’ll want to be careful when it comes to plants.

Black mystery snails love to munch on plants! If you plan on adding these snails to a planted tank, be warned - these snails may consume some of your plants! You can lower the chances that they’ll eat your plants, by providing them with a steady supply of food and algae.

Hardscape options for black mystery snails include rocks and stones, but you’ll want to avoid Seiryu stones , which are capable of lowering the pH, creating a dangerous acidic environment for your black mystery snails.

Creating a unique aquascape is not only visually appealing but having a tank with plenty of stones and driftwood means more surface area for algae to grow and develop, providing a nutritious diet for black mysteries.

Common Diseases

There’s not much you need to worry about regarding diseases. Black mystery snails are resilient against most diseases and parasites, but you’ll still want to make sure you maintain proper water conditions.

More than likely, if you’re keeping other tank inhabitants, they will show signs of disease or stress before a black mystery snail. You can ensure that you are always maintaining a clean aquarium, by consistently testing your water quality with a reputable aquarium test kit .

Although it’s not necessarily a disease, if you’re a planted tank owner and plan on keeping black mystery snails, you need to be extremely cautious if you plan on injecting CO2. Planted tank hobbyists often inject CO2 directly into the water column to promote plant growth, but this CO2 injection can lower the pH, which can be deadly for black mystery snails.

Always increase CO2 levels slowly when adding new inhabitants, and monitor these snails closely for signs of stress. If CO2 levels are starting to reach dangerous levels, you will notice your black mystery snails attempting to climb to the top of the aquarium, where oxygen is more abundant. If you encounter this problem, reduce CO2 levels. If you need to immediately reduce CO2, you can perform a 30% water change.

Food & Diet

Black Mystery Snails are very undemanding when it comes to food. Most of these snails can exist by living solely on algae and leftover fish food. To ensure they’re getting the correct amount of nutrition, you can supplement their diet with sinking invertebrate pellets, algae wafers, and even blanched zucchini!

Aim to feed your black mystery snails at least once a day, but you don’t need to worry if you can’t feed these snails for a few days, they’ll be perfectly fine consuming any available algae until you’re able to resume feeding.

Behavior and Temperament

You might be surprised to know that observing a black mystery snail can be quite entertaining. These snails are notorious for climbing up the sides of an aquarium, only to release themselves and fall to the ground! These snails are also known to recede into their shells if they’re threatened, but some will even recede when they’re just looking to rest.

When they’re active, they can be quite mobile, and they will occasionally swim to the surface to grab some fresh oxygen. They’ll also occasionally float, as air can get trapped in their shells, making them more buoyant. Rest assured, they’ll only float temporarily, and should eventually drop back down to the substrate.

Tank Mates

Mystery snails are compatible with any species that wouldn’t consider them a snack. Peaceful nano schooling fish will do well with black mystery snails. Other potential tank mates include:

There are certain species that you’ll want to avoid. Large aggressive fish will nip and pick at mystery snails, so avoid species like:

Make sure to avoid adding any assassin snails, these snails have a built-in stinger that can attack and kill any mystery snail they encounter!

For the most part, you shouldn’t have a problem keeping black mystery snails with other peaceful fish species. You can even keep black mystery snails with other types of mystery snails! The possibilities are almost endless.


Breeding mystery snails is simple, any hobbyist can do it. It’s more common to accidentally breed black mystery snails than to intentionally breed them!

All you need to do is have at least one male and one female black mystery snail. Eventually, they’ll cross paths and breed! You’ll know the eggs when you see them. Snail eggs appear as small white dots, encased in a gelatinous goo, that is often found on the aquarium glass or substrate. After a few weeks, the snail eggs will hatch, and the baby snails will begin to move around the aquarium.

That’s all there is to it. As long as your water conditions are in good shape, breeding black mystery snails is a breeze!

Frequently Asked Questions

Black mystery snails are popular for a reason, people love the way they look and their ease of care. However, there are still some common questions asked by hobbyists that often go unanswered.

But don’t worry, we’re going to do our best to answer them!

How long does it take for black mystery snail eggs to hatch?

Black mystery snail eggs typically hatch in 2-3 weeks. It’s easy to miss the exact time they will hatch. Keep an eye on the egg sac, if it appears that fewer eggs are present, you more than likely have some baby snails exploring their new home!

Why is my black mystery snail so small?

Black mystery snails are typically sold as juveniles. They won’t reach their full size until they’ve been alive for at least a few months. Feeding black mystery snails a nutrient-rich diet will ensure they grow to their adult size, which is usually around 1.5 inches.

Where can I purchase a black mystery snail?

Black mystery snails can be purchased on online marketplaces, such as eBay and Light Fish.They can also occasionally be found in local fish stores and can sometimes be found for sale at aquarium conventions.


As you can see, black mystery snails are a must-have in an aquarium. They’re fun to watch, and their shells have plenty of unique naturally occurring patterns and colors. We guarantee after purchasing one of these snails, you won’t regret the decision. Whether you’re just getting into the hobby, or you’re an aquarium veteran, the black mystery snail is a species that can be enjoyed by almost anyone.

We hope you enjoyed reading this guide. We love to hear from our readers on Instagram, and we always welcome guest posts on our community site. If you have specific suggestions or feedback, you can also send us an e-mail!

Ashley Briggs

Miles Harrison

With over a decade of aquarium experience, Miles can be found writing about saltwater and freshwater aquariums. When he’s not writing about fish, you can find him going for a run or building websites, such as this one!