Mystery Snail: Care, Food, Tank Setup, Breeding, Illnesses

Mystery snails are awesome!

While not the most voracious algae eaters, they clean detritus and decaying plant matter, add a lot of color and character to the tank, and snail-dive like crazy.

Taking care of mystery snails isn’t the easiest thing in the fishkeeping world — they aren’t guppy, after all — but it isn’t that difficult either. Their basic needs are:

• Clean water — Good filtration and regular water changes
• Hard water — high KH (5-18) and GH (5-15)
• pH above 7
• Temperature between 20°C-26°C or 68°F-78°F; they can tolerate even a few degrees higher temperature
• Food — Veggies, wafers, and protein
• Peaceful company

Depending on your aquarium setup, mystery snails (or any snail, for that matter) may need additional calcium and minerals to maintain their shells healthy. Aquarium snails aren’t like shrimp and don’t change shells.

Instead, they grow together; keeping their shells healthy means keeping the snail healthy.

But let’s dig deeper to understand how to care for mystery snails, what food they really like, how to sex them, whether they get lonely, and some of the most common issues you may face with these cute little critters.

Mystery Snails Anatomy and Behavior

Mystery snails come in various colors. Yellow and brown are the most common hues, but there are blue, white, black, jade green, purple, and more. 

Their shells can be a single, continuous color or may sport darker lines here and there. 

The shells are round, with an operculum that can seal off the snails completely. The operculum is dark brown or black, and it is made almost entirely of protein, much like human nails. This shell door is the main reason why mystery snails need protein in their diet.

Originally from the Amazon basin, Pomacea bridgesii are also called Inca snails.

• Common names — Mystery snail, Inca snail, apple snail
• Species name — Pomacea bridgesii
• Size — 3-5 centimeters or 1.5-2 inches
• Lifespan — 1-1.5 year
• Origin — The Amazon, Brazil, Bolivia, Paraguay, Peru

They are active mostly at night, but you can see them roaming around in the day too. Mystery snails have relatively poor eyesight, despite the fact their eyes extend far from their bodies, mounted on moving antennae. But while these snails are far from the champions of underwater vision, they do detect sudden changes in light.

On the other hand, they have an excellent sense of smell. Drop a bleached zucchini and watch them run to it.

And run they will because as far as snails are concerned, the Inca snails are among the fastest species.

Not fast enough to jump out of the tank, but since they have both a gill and a lung, they are not strangers to roaming outside of water.

Keeping a lid on at all times is a must.

Mystery snails are often confused with their larger cousin, the apple snail, but in reality, they are different species. Apple snails are considerably larger and more destructive for aquarium plants.

Mystery Snail Water Parameters and Tank Setup

The tank setup for mystery snails should include good filtration, substrate without sharp edges, and hard water. Sand, gravel, and pebbles are all fine for the mystery snails, and so are specialized aqua soils.

• pH — 7.1-8.5
• KH — 5-18
• GH — 5-15
• Temperature — 20°C-26°C or 68°F-78°F
• Preferred substrate — Any, mystery snails don’t rummage through the substrate as much as rabbit snails or Malaysian trumpet snails
• Lighting — Any as mystery snails have poor eyesight and light isn’t their primary sensory input anyway

Now, the water temperature mystery snails can live in stretches up to 28°C or 82°F, but their ideal range is between 22°C-24°C or 72°F-76°F. Keeping them at low temperatures slows down their metabolism and potentially stretches their lifespan. More importantly, slowing down the snail growth allows them to form healthier, stronger shells.

The snail body can grow faster than the shell because the latter needs time to form and solidify.

However, keeping them at very low temperatures will hibernate the snails.

pH levels should be neutral or basic. The necessary water hardness should buffer things up nicely, allowing for a stable environment and thriving snails.

A clean water column is crucial to the survival of mystery snails. Good filtration and regular water changes are necessary as the snails are quite sensitive to polluted water.

That’s the very reason why it is hard to tell how many mystery snails per liter or gallon of water will feel comfortable. The general wisdom is that a single snail needs 5-8 liters or 1-2 gallons of water, but if you do regular water changes and provide strong filtration, that number can increase. Conversely, weak filtration and rare water changes would push the volume up.

When it comes to stocking, count the snails as medium fish to get a better estimate for a community tank.

Calcium in the Water Column

Like most aquarium snails, Inca snails require calcium to grow their shells. Adding crushed coral or cuttlebone helps a lot in that regard. Naturally, calcium supplements also work fine.

Another, arguably more accessible solution, is the addition of crushed egg shells. Boiled eggs are safer to use, as they have been sterilized in the cooking process. It is better to remove the membrane inside the shells before adding it to the tank. If a bit of membrane is left, it is not a big deal, as the snails will eat it.

It is a good source of protein, but if it is too much it may foul the water.

Raw eggs will also work, but it is best to toss the shells in the oven for 15 minutes or microwave oven for a few minutes of sterilization.

Crush the eggshells. Reducing them to fine pieces in a food processor allows for the shells to enter the substrate more easily. Besides enriching the water column for longer, shells incorporated in the substrate make for a much more pleasant viewing in a display tank.

Mystery Snail Tankmates

Mystery snails are super peaceful critters and appreciate similarly predisposed company. Yo yo loaches are out of question and so are carnivorous large species.

A peaceful betta in a large tank could do. Tetras, corydoras, guppies, plecos, danios, gouramis, and mollies will do just fine.

The mystery snails can live with any other type of snail besides assassins.

Mystery Snail Food

One of the most common reasons why mystery snails wither and die is insufficient food. While fish commonly suffer from overfeeding, many hobbyists underestimate how voracious snails truly are.

For starters, let’s clarify what the Inca snails don’t eat. They don’t eat healthy plants and most algae types. You may see mystery snails nibble on a plant, but that is a strong indicator that the plant is experiencing some discomfort. These snails simply don’t bother healthy plants, with duckweed being the only exception. Not all mystery snails eat it, but those that like it really enjoy it.

And while mystery snails will clear out some algae off the glass, they aren’t particularly enamored with hairy algae or, again, healthy plants, which most algae are.

They love some blanched veggies, though. Give the mystery snails blanched zucchini or cucumber and watch them devour it. Algae wafers would also do and so will frozen or live blood worms.

Remember, the snails need a good amount of protein to keep their operculum intact.

Mystery snails can last relatively long without regular feeding as they scavenge around the tank for uneaten fish food and decaying plants. However, if you want them to grow and live over one year, make sure to feed them regularly with blanched veggies, the occasional protein snack, and other sinking food.

To prevent the fish from consuming everything, feed the snails at night when the lights are out and most fish sleep.

Mystery Snail Poop

Mystery snails are scavengers that naturally clean a fish tank. However, they also have a relatively inefficient digestive tract. In other words, they poop a lot, as they can’t process much the things that enter their mouths.

Their sticky poop accumulates quickly, which is one of the main reasons why they need regular water changes (and good filtration).

It’s not all bad, though! The inefficient digestive tract is a good breeding ground for infusoria, which is expelled with the snails’ poop. That makes mystery snails a particularly handy addition to a fry tank, as the baby fish will eat the infusoria happily.

Mystery Snail Lifespan and Growth Rate

Mystery snails usually live up to a year. In lower temperatures and with a proper diet, they could live a few months more.

The growth rate of the mystery snail depends on water temperature and diet. Lower temperature slows down their metabolism and their growth. The good news is that slower growth is actually beneficial — it allows the shell to grow thicker and stronger. This way the snail will be able to withstand potential mineral deficiencies in the future.

On average, the mystery snails grow to full size in about two months after hatching. Their maximum size doesn’t exceed 6-7 centimeters or 2-3 inches in diameter.

Mystery Snail Breeding

Mystery snails reproduce relatively easily. They aren’t as prolific as some pest snails, mostly because they have fixed sexes. Telling apart the male from females isn’t easy, as it requires a lot of careful observation.

The males have their “penis” on the right side, but it is usually well within the shell and hard to spot. The female mystery snails are much more prone to scale up the aquarium walls, as they lay their eggs outside the water.

As with most snails, the main condition for snail offspring is food. If you feed your Inca snails well, they will try to lay eggs.

However, you must leave at least 8-10 centimeters or 3-4 inches between the water line and the lid for the females to lay their cluster of eggs. The eggs look like a clump of white dots. It needs humidity and will hatch in 2-4 weeks.

The first few times they will likely lay 50-100 eggs but as the snail grows so will their reproductive profligacy.

What’s more, female mystery snails can store sperm for weeks on end. Once impregnated, they can lay eggs several times.

The little hatchlings eat practically the same food as their parents. Make sure to keep them out of fish’s reach or else they’ll quickly become food themselves.

Another useful precaution is to put a fine mess or another barrier at your filter’s intake, as small (and no-so-small) mystery snails may crawl inside and die there, compromising the filter.

Mystery Snail Sicknesses

Mystery snails are rather sensitive to changes in the water parameters. Stable, clean water will keep them healthy, but sometimes you may see them suffer.

The most common and visible ailment is a wavy foot. It indicates poor water conditions or a contaminant the snails are very sensitive to. Mystery snails have an extremely low tolerance toward copper and aquarium salts, so keep their water free from those.

A few small water changes should fix the issue. Sick snails are even more sensitive to changes in the water chemistry, so it is always advisable to perform a few small changes (15%-20%) instead of a single large one.

A receding operculum may indicate protein insufficiency. Feed the snails protein-rich food to see if the operculum recovers, but it could also indicate a more natural end of life — from old age.

A cracked shell can indicate several severe issues. Add immediately calcium, ideally pure calcium powder. Eggshells need some time to make an impact and may not be quick enough. Deteriorating shells can easily kill the snails.

When Buying Mystery Snails

Mystery snails live about 12 months on average, but they reach maturity within the first two months. Grabbing a fully-grown snail is the safer option as growing individuals are more susceptible to unfavorable water conditions.

Look for snails that are active, with good-looking shells. Even the smallest crack or break indicates some issues. Don’t be afraid to spend a few minutes observing the little crawlers. Now that you are familiar with the mystery snail anatomy, you can deduce whether those displayed in the store are healthy, with the prerequisite number of antennae and eyes.

Mystery snails can grow back missing appendices, but it is best to take care in advance and make sure they reach your tank in prime condition.