Mystery snails are one of the more common freshwater mollusks found in our tanks. Despite how common they are, the mystery snail lives up to its name for many aquarists. There’s a little bit more to these guys than meets the eye, and you’ll be well served by learning a bit more.
So, if you’re ready to learn more about the much-vaunted mystery snail and its care, read on!
Mystery Snail Quick Facts
Common Name: Apple Snail, Spike Top Apple Snail
Scientific Name: Pomacea bridgesii
Size: 2” Shell
Care Level: Easy
Origins of the Mystery Snail
The Mystery Snail is a simple mollusk, one of the most common snails seen for trade. They’re not quite the most common snail in freshwater tanks, mainly because they require a little bit more attention than the common plant-riders like Ramshorn and Pond Snails.
Pomacea bridgesii is native to South America, coming from Brazil, Paraguay, and Peru. They’re invasive in a few areas, including southeastern Asia, and in Hawaii. This established presence in foreign areas shows they’re adaptable in addition to showing how tight controls on mollusks should be implemented in your aquarium.
The species is also known as the Spike-top Apple Snail, or just the Apple Snail. Many of those you’ll see in stores are the golden variety, but there’s actually a surprising amount of different colored shells available. The rarest of these are purple.
Their bodies will either be dark colored, which is “normal” or light colored. Technically the light-colored bodies are often albino, but the internals of the snail will make a light body appear to be a pale shade of yellow or green in most cases.
There are quite a few different color variations, with some of them considered rare. I’ll discuss these below.
Mystery Snails are hardy creatures, able to be dropped in most aquariums and ponds without a lot of preparation. The only common issue that may be serious is water with a low pH. Low pH, soft water has a tendency to eat up snail shells, weakening them over time and affecting new growth.
You can often find these snails for just a couple of dollars at pet stores. They’re particularly common in LFS. It’s easy to get the exact snail you want and their common nature allows you to be picky. So… be picky. You probably have a few thousand snails to consider between the LFS and big box stores in your area.
Mystery Snails aren’t the best cleaners available, even for snails. While larger, they don’t breed as prolifically as Ramshorn or Pond snails. The latter two will usually have a population explosion followed by a decline in tanks with an excess of detritus. Mystery Snails are a bit more complicated to breed. They also don’t breed at the same rates.
I’ve often used them as an additional centerpiece creature in planted tanks. A good stocking level for these creatures is 1 per 5-10 gallons. I prefer the latter edge of the range, most Mystery Snails will end up being at least twice the size they were in the store. If you stock them at 1 per 5 gallons you may need to supplement their diet.
Overall the Mystery Snail is a hardy, relatively large freshwater snail. They have minimal care requirements as long as water quality is in order, and there are many different color variations that show up due to the way the snails’ genetics affect their coloration.
How Water Conditions Affect Snails
Freshwater snails need a couple of things in their water to make sure that they’re healthy.
The pH of any tank containing snails should be 6.5 at the lowest unless otherwise indicated. This is to ensure that the water doesn’t eat at their shells, which will happen with an acidic pH (ie: lower than 7.0). This is a slow process most of the time, but eventually, it will eat through the shell.
They also need a good deal of calcium to make up their shells. Shells are made up of calcium carbonate, usually in the form of aragonite or calcite. This biomineralization process is fascinating and required for the snail to live. They receive this material from calcium in the water column.
So, for once, having hard water can pay off.
At least if the hardness is caused by calcium and not just magnesium and potassium salts. In very rare cases hard water may need some form of calcium to keep snails, but I’ve never seen a case personally.
Snails that are in an acidic pH will suffer from thinning shells. This usually shows up as “bleaching” of the shells as they wear through. If your snail begins to show growing white patches on their shell you should test the pH of the water. Especially if you know the water is hard from the source.
On the other hand, a lack of calcium will cause very slow growth. Deformities in the shell may also appear at more extreme levels of calcium deprivation, as the shell is forced to keep growing without enough calcium to put it in its proper form.
Snails may also act lethargic when they don’t have the nutrients they need. Most snails are relatively active creatures, if yours is spending large amounts of time in its shell or is slow to respond to external stimuli there may be a problem.
The big thing is just to make sure you have water with a neutral-ish pH and sufficient calcium levels for your snail or you may run into problems. Keep an eye out for faded shells, slow growth, and lethargy.
What Does Your Mystery Snail Actually Need?
Mystery Snails don’t need a lot, especially compared to fish and other complex organisms.
At their most basic, a snail needs the following:
- Sufficiently clean water
- The correct temperature
Without these, the snail will die. With them, the snail will be fine.
It’s rare that you’ll have to change anything about how your tank operates from adding a Mystery Snail. If your tank has the basics then the snail will be fine.
Water and temperature are easy. Get the tank cycled and put in a heater and it’ll work fine.
Food usually isn’t a problem, but you may want to go a bit above and beyond just dropping in some flake if you’re planning on breeding them. In this case the occasional addition of raw leafy greens or blanched vegetables will help keep them extra healthy.
If you’re just raising them in a tank without care for their breeding habits, however, then they’ll usually be content to rummage through whatever is being fed to the rest of the critters in the aquarium.
Mystery Snail Tankmates
Mystery Snails are tough enough to handle most common tropical fish, while also being harmless to the rest of them. That doesn’t mean they’re completely in the clear for placing in tanks, however, as you need to keep the safety of the snails in mind.
As a general rule, the only thing to make sure of with fish less than 3 ½” is that they’re not a species that naturally eats snails. Fish larger than that should be judged on a case-by-case basis, primarily on mouth size.
Temperament also matters, I kept Mystery Snails with an Oscar for years but they were eaten in short order when I introduced a Green Terror. The Green Terror was about half the size of the Oscar, and I was a bit surprised.
Some species that absolutely aren’t compatible with these snails include the following:
- Pufferfish (Any)- Even the diminutive pea puffer will kill Mystery Snails. Pufferfish are well adapted for eating shelled creatures such as snails due to their incredibly strong beaks. They really shouldn’t be kept with any invertebrates without extensive research and careful selection.
- Mbuna Cichlid- Prolific snail eaters in many cases, particularly in mating season. It’s best to just avoid them for any tank containing Mystery Snails.
- Loaches- Loaches like to eat snails, and any that are large enough will go for your Mystery Snails without a second thought. Smaller loaches may be harmless to your snails but it can be a hard thing to balance.
- Catfish– As a general rule, catfish will eat just about anything slow enough to be caught. Mystery Snails fall under that definition and any catfish over ~4” should be considered a threat to them. Corydoras and other small species will eat baby snails but are unable to harm full-grown ones.
And, of course, you’ll want to be careful about any fish that are too large. Things like a full-grown Arowana can easily eat a Mystery Snail if they want to. Size matters a lot in this case, as the majority of fish we keep are opportunistic predators, and definitely not averse to the taste of escargot.
Breeding Mystery Snails
Breeding these snails can be quite rewarding, but it does amp up the difficulty level a bit.
Housing Your Snails After Hatching
The first thing to keep in mind is that you’re going to end up with dozens to hundreds of Mystery Snails when you’re done. It’s likely you’ll end up with an essentially endless supply once you start, so you need to find somewhere to place them.
Snails rarely put much bioload into the system, but Mystery Snails are large enough to have a heavy impact. You’re pushing things a bit with one per gallon so you need considerable open tank space or someone who does and is willing to take them.
I recommend talking to the owner at your LFS and inquiring about whether or not they’d be interested in a supply. They’re not worth a ton, but you may be able to make out well in store credit. This depends on the owner you’re dealing with, of course.
Set Up the Breeding Tank
Next up you’ll need a dedicated tank for your snails and to make sure that there are males and females in it. How do you tell them apart?
Most of us don’t.
Instead, you’ll want to just put in a group of them and let things play out. Unlike land snails, which are hermaphrodites, these snails have a fixed gender. The males have a penis sheathe which can be seen from the front of the shell but it’s hard to detect without some form of magnification.
Your group of snails should be in hard water for the best results. They’re going to go through a lot of calcium very quickly as the eggs hatch and the young grow, the hardness will give you more wiggle room to avoid problems in development.
One of the best things you can give your snails when mating them is spinach. It contains quite a bit of calcium, which will help them develop properly. Without the calcium, your snail’s shell will have a lot of problems forming, and it can lead to permanent disfigurement.
So, just supplement their diet with leafy greens during the mating process.
If you’re worried about overfeeding then just make sure to test the water for nitrates. You should have the same standards as you would for a fish, don’t let things slip just because your snails don’t swim. Less than 15ppm is ideal and less than 20ppm is acceptable. Anything higher and you should spend some time to sort out the problem before it becomes serious.
Breeding for Color
Mystery Snails come in quite a few different colors. Much like Ramshorn snails, Mystery Snails have both body and shell color to take into account.
It’s simple enough to learn how to do this, it’s the same basic idea behind breeding guppies and Betta for specific visual traits. Specifically, you’ll want to learn the basics of Mendelian inheritance if you don’t remember your high school bio classes all that well.
There are both common and rare types of these snails. Most of those sold in pet stores will fall into the ivory or golden color spectrum, with blue specimens periodically available as well. Your LFS may have better options, but you’ll see those three in any type of big box store.
The rarest among them is actually the Light Striped Purple morph. This Mystery Snail will have a white shell with purple stripes running along it. It’s a good goal to aim for, but do some digging since there are over a dozen recognized variations.
Line breeding will take a bit more work, especially since you need to definitively sex the snails and mix them together carefully. Remember that snails can hold onto their eggs for a good while, which means that the first clutch may be from a different male than the one in the tank.
With a little bit of effort, and a lot of record keeping, you can eventually open up the path to any color morph found in these mollusks.
Not So Mysterious
The Mystery Snail is often overlooked, but it can be a great part of most community aquariums. There’s a color variation for almost everyone out there, and they’re very simple creatures to keep as long as you have good water parameters for their health. Add in a bit of line breeding and you have a surprisingly complex creature that can be a lot of fun for the hobbyist.
So, are you planning on finding your own Mystery Snail for your aquarium?