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Marisa cornuarietis
Marisa cornuarietis

If you have a question regarding apple snails and you cannot find the answer in the other pages you have arrived at the right spot.
In this page the most common questions and their answer are listed and there is also an option to post a new question (or comment) at the bottom of this page. However, please take a look to see if your question isn't already listed here before mailing me.  And please consider posting a message in the Apple snail discussion board instead.
Note that I do not mind to answer questions or to receive comments, on contrary, but it's quite boring to get the same questions over and over again.
If you find it hard to locate specific information, go to the index page, were a keyword-based index and a site map are available.
Other pages that contain valuable practical information are:

For a translation of this page: look here (with thanks to Anna Galovich, who also translated this page)

Pose a question here...

 

 

Q:How do I know if my snail is an apple snail?

What exactly should I feed my apple snail? I place romaine lettuce at the bottom. Is that good enough?
A: From my own experience, the apple snails are not difficult when it comes to food.
Feed them fish-food (food for pond fish, it comes in a big box, consist of big pellets and is inexpensive), cucumber and lettuce.
Apple snails consume a lot of aquatic plants and algae and can be very useful in eliminating your algae.
In the literature there is an article mentioning that their apple snails stopped reproducing when they where put on a diet, which consisted solely of water hyacinths. They didn't describe if it was the kind of food, or the fact that they could only eat one type of food that caused it. 
Maybe it might be a good idea to have some variation in their diet.
Related: 'Care' section and 'Quick guide' section.

Do Apple Snails eat aquarium plants?
A: This mainly depends on the species, most species are likely to consume your plants to some degree, while other species don't. Have a look at the Care to find out how to feed your apple snails.
Related: 'Care' section and 'Quick guide' section.

Are apple snails hermaphrodite?
A: No, apple snails are not hermaphrodite like some other snail families (mainly land and freshwater species). This means you'll need a male and a female to get baby snails.
A sex change from male to female has been described for some Pila and Pomacea apple snails. In case of Pila snails, the male needs a preparatory aestivation period to become a female, while the Pomacea snails can possibly change sex at all times. The frequency at which this sex change occurs is not certain.
Related: 'Reproduction' section.

How can I see if a have a male or a female apple snail?
A: A relative easy (?) way to determine the sex of an apple snail is by taking the snail out of the water, keep it on it's back and wait until the animal comes out of its shell. At that moment you have to take a look at the upper part of the right mantle cavity. Close to the edge of the shell, you can see the penis sheath starting (take a look at the anatomy to get an idea where to look for).
Some experience might be needed for this, but once you have seen the difference between the male and the female snail you'll find it less difficult to determine the sex of an apple in the future.
Another option is to wait until the snail copulate. When they're mating, the male snail creeps on the shell of the female and puts his penis in her. At that point you know that the one on top is the male and the other is the female.
The third way to differentiate the sexes is based on the fact that male snail have a rounder shell opening (aperture). In the case you are the lucky owner of several apple snails, you can compare the aperture height/width to determine the sexes of your snails.
There also is a fourth way: killing the animal and having a look at the inside. But I guess you prefer to keep your snails alive.
Related: 'Reproduction' section.

I'm planning to buy a couple of apple snails. How to control the snails once they start reproducing?
A: Most apple snail species deposit their eggs above the waterline. The eggs can be easily recognised (look at the pictures on this site) and if you remove them regularly, you won't have a problem at all.
Besides this, keep in mind that apple snails are rather big and can be easily spotted (especially the lighter, yellow varieties) and removed by hand.
Related: 'Snail eradication' section.

Do I need to make a place for my snail to lay her eggs? Maybe something out of the water?
A: There is no need to create a special place for the snails to lay their eggs on. Just leave some space between the waterline and the cover-plate of your aquarium. The snails prefer smooth surfaces like glass above rough objects like wood and stone.
The species that lay their eggs below the surface like the Marisa genus don't have a need for a large air space between the cover and the water surface.

My apple snail keeps growing. How big can I expect them to get?
A: When the conditions are good, the apple snail species Pomacea maculata can get as big as 15 cm/6 inch diameter. Other species don't grow that big, but there is a big variation between them. Rather expect them to get 5-8 cm/2-3 inch diameter.

One of my snails has lost a part of its tentacle. Will it grow back?
A: Yes, maybe it won't get as long as it was before, but snails have a remarkably ability to repair their body. They can even regenerate a lost eye within 25 days. The regenerated body parts are often somewhat smaller than the original.
Related: 'Diseases' section.

Are there sorts of fish I have to look out for that could eat my snails?
I have noticed that some species try to eat their tentacles.
A: Many fish species consider the tentacles of an apple snail as attractive pieces of food and at least try once in a while to eat the tentacles. Losing a part of a tentacle might not be a pleasant experience for a snail, but as snail have a remarkable ability to regenerate lost tissues, it's not a life-treating problem. The snails also adapt their behaviour to overcome the tentacle nipping: they keep their tentacles under their shell and they react quicker to water movements with retraction in their shell.
It often stay at the level of tentacle nipping, but some fish species go beyond that point and try to eat the whole snail. Especially bigger fish species with strong jaws (like cichlids) can be a threat to your apple snails, at least if they manage somehow to damage the shell enabling them to reach for the soft snail tissues. 
A list with known apple snail predators is included in the 'Ecology' section. 

How well can an apple snail tolerate cichlid-salt?
A: Apple snails tolerate little amounts of salt if you slowly build up the concentration. Be sure that the salt is dissolved before you put it in the tank so that the snail won't get in contact with the pure stuff.
If you see that the snails stay in their shell for more than a day, then lower the salt concentration (if it isn't too late :-).
Experiences with apple snails and salt from a reader:
"My pond contains several very large koi and we routinely use salt to control parasites.
I'm happy to report that my apple snails tolerate 0.3% (3 lbs per 100 US gallons) of salt very well.
We dose 0.1% ever 12-24 hours for 3 treatments.
As a side note, this also seems to kill the snail parasites as well.
    Roark
"

Are apple snails an intermediate host for (fish) parasites?
A: There are several parasites that have snails as an intermediate host. However, apple snails are relatively resistant to many of these parasites, which are often host specific and do not regenerate in other hosts like apple snails. 
However, at least one parasite (Angiostrongylus cantonensis, a nematode, also know as the rat lungworm), uses the apple snail as an intermediate host. This parasite has the rat as its main host, but humans can be infected when raw snails are consumed. In rare cases this infection can cause eosinophilic meningonencephalitis resulting in severe neurological disorders and even death.
But don't worry if you got your snail from a pet shop, the only way the snail can be infected is by living in water were infected rodents (rats or mice) live. And even then, you have to drink the water or eat the snail or your water-plants (on which the parasites attach themselves after finishing their life cycle in the snails and wait there for being eaten by their main-host).
If you suspect your snail from being infected, just keep them away from their main host. This breaks the life cycle of the parasite, and you will get lost of them. Beware that it can take a long time, because many parasites are able to have several generations in their intermediate host. Better thing to do is waiting until the snail has laid their eggs and go on with the young, uninfected snails.
More detailed info on Angiostrongylus cantonensis can be found at: http://www.cdfound.to.it/HTML/ang.HTM.
Related: 'Parasite' section.

Are mystery snails also apple snails? Or are they different types of snails?
A: In some sources the name apple snail and mystery snail are considered to be synonyms for the snails of the family Ampullariidae. The name apple snail refers to there size, colour and form, while the name mystery snail comes from the fact that the aquarium market didn't know what kind of snail it was or where it came from, so it was a mystery (snail) for them.
In other sources, the mystery snails are described as snails from the family Viviparidae. The snails from this family look very similar to the snails from the family Ampullariidae, but they do lack a lung and labial tentacles and are livebearing snails (hence the name Viviparidae).
Most snails sold as 'mystery snails' in the shops are Pomacea diffusa snails.
Related: 'Species' section.

Do apple snails hibernate? Or are they active during the whole year?
A: Several snails of the genus Pomacea aestivate buried in the mud depending on the temperature and the amount of available food and water, whilst in other regions the same species are active during the whole year. So apparently it's not necessary for them to hibernate. Rather consider it as a survival strategy that's only used during difficult periods of scarcity.
Related: 'Ecology' section.

I bought an apple snail and the new part of its shell is growing in a lighter colour and also irregular. What could be the cause?
A: It is because they have stopped growing for some time (transport to the shop, lack of food, other water quality) and when the animal start growing again (thanks to your good care) it's unable to make the same quality of shell as it was before. When you get young snails, hatched in your own tank, you'll see that their shell gets the right colour and that they grow more smoothly. But keep in mind that some species are more vulnerable to get a less smooth shell especially when they get older.
Related: 'Shell' section and 'Diseases' section.

The older part of my snail's shell is getting little surface holes. Will my snail suffer from this?
A: It's not uncommon for certain species of apple snails to have parts of their shell dissolved. In the apple snail disease section, you can see an example of this natural occurring surface damage.
The shell of an apple snail consists of a colourful organic outer layer, this layer is created first and in a later stage the snail creates the strong, calcium-rich innerlayer. However, the colourful outherlayer is not very resistant to mechanical damage and subsequently as the snail gets older, this layer tends to become thin and even completely absent at certain places. At that point, the calcium based innerlayer is exposed to the water and can dissolve is the water does not contain much calcium and the shell then gets small pits, which can be described as 'wormholes'.
Well, to this point, one cannot speak of a dangerous problem, as long as this process is slow and the snail gets enough time to reinforce the innerlayer by adding more calcium. Nevertheless, when the decay of the snail progresses too quickly, the snail gets real holes in their shell. This doesn't mean that the snail will get in trouble as long as the holes aren't too big. The snails often don't seem to suffer from it and after a while they make a calcified layer on the exposed tissues and sometimes even manage to repair their shell by creating a new layer at the inside of the shell. .
You can try to repair the holes by attaching some pieces of shells from other snails with superglue. I did this several times without problem as you can see on the disease section.
Be careful that the glue doesn't come in contact with the snail tissues or your snail might get killed!
One of the readers of this site also has experiences with repairing snail shells:
"I had one of my large apple snails (about 4", 4 years old) partly crushed. I used 'superglue' (cyanocrylate) to put his shell back together. Fortunately, he wasn't damaged internally and this reconstructed shell worked very well. I also put him on a diet of algae tablets and canned spinach. In six weeks he had regrown enough of his inner shell to hold himself together and I was able to stop reglueing. He's doing well a year later.
    Roark
".
Better than repairing the shell is to avoid problems by keeping the calcium concentration of the water high enough to inhibit and prevent shell dissolving.
A higher calcium concentration can be easily achieved by adding calcium carbonate to the water. Many aquarium and pond shops sell special preparation to increase the calcium concentration. However, crushed or powdered marble, seashells, limestone and eggs shells are useful alternatives.
Before you starts to add calcium supplements, make sure that the other inhabitants (fish) of the tanks/pond tolerate calcium rich (hard) water and remember: 'if it ain't broken, don' fix it'. 
Related: 'Shell' section and 'Diseases' section.

My apple snail lost the top of its shell. Will it grow back?
A: No, although the apple snail is able to repair holes in its shell by making a new calcified layer on the exposed tissues, it won't be able to create a new shell top (click here to see an example). 
It might look terrible, but most snails don't suffer much from losing the top of their shell.
Keep in mind that the shell has two main function: protection (against predators and drying out) and support (keeping the mantle cavity with the lung and the gills open). And as long the shell is providing these functions sufficient, there is no problem.
If the damage is very big, you can try to glue the top from another shell over the top of your snail's shell. If you go for this option, be carefully not to let the glue come in contact with the snail tissues or you might end up with a dead snail and another empty shell after all (click here to see an example). 
Related: 'Shell' section and 'Diseases' section.

I noticed an empty shell in my aquarium. Do other snails or fish eat the body of a dead snail?
A: Many (also non-apple) snails eat the body of a dead snail and so do some fish like the Siamese algae eater. Not to forget the enormous army of bacteria and other micro-organisms that is heading towards the dead snail and helps to decompose it quickly.
But at the other hand it's also good to realise that an apple snail body mainly consist of water and decays quickly, without leaving much behind.
Also, remember that the apple snail is attached to its shell with a strong muscle (the columella muscle). Once the snail is dead, this muscle weakens, breaks and the body comes out of its shell.

How old do apple snails get?

The apple snail's life expectancy mainly depends on the temperature of their environment and the general life conditions. At lower temperatures, the apple snail can get over 3 years old and records of apple snails of ten years old have been reported. Lanistes nyassanus has an estimated life span of 5 to 10 years in Lake Malawi, Africa.
At a temperature of 25C, they will only live 12-16 months. At higher temperatures, the snails are more active because their metabolism increases with the temperature, but this also speeds up their life cycle and thus shortens their life expectancy.
So you can elongate your snail's life by lowering the temperature. A general rule: keep the temperature between 18 and 28C (65-82F).
It is suspected that at least some apple snail species need an aestivation period in the mud to avoid burning-out.
Related: 'Ecology' section.

Will my apple snail survive the cold winter months in my pond? Or should I take the snail out the pond during this period?
Apple snails are tropical animals that require temperatures between 18 and 28C (65-82F) to stay in good condition.
If the temperatures drops below 10C (50F) the apple snail becomes completely inactive and will die within a few days.
Take your apple snail out of the pond when the temperature drops below 18C/65F in the winter season.
Related: 'Care' section and 'Quick guide' section.

My snails are inactive for most of the time. Am I doing something wrong? The temperature is OK and the fish seem to be healthy.
Apple snails are rather lazy animals, they only creep around if they need to. In other words, when they are hungry or want to reproduce themselves.
If they have plenty of food, they will show almost no activity (why should they?).
In the case this inactivity sounds familiar to you and you worry about their inactivity, just reduce the amount of food for a week and see if that makes any difference (also check them at night!).
Another cause could be low temperatures. Make sure that the temperature stays between 18 and 28C (65-82F).
Also there might be an activity difference between species as reported by H. Auer. His Pomacea glauca is being the most active, second in rank this Pomacea flagellata and lowest activity showed by his Pomacea diffusa.
Related: 'Diseases' section.

My snail is floating around for a day now. Is he/she dead or what? What should/can I do?
Well, apple snails can be very inactive for days (see answer above this one) and if they have a lot of air in their lung, they float (sounds logical isn't it?). Floating of an apple snail doesn't indicate that there is something wrong or that he/she is dead.
To check if the snail is alive, take it out of the water and see if you can get it moving by touching the shell door. If the shell is closed completely, then you can be sure that the snail is alive because once the snail is dead, the muscles are relaxed and the shell door stays at least partly open.
Another way to check the snails is by looking at the heartbeat (only possible with young snails and snails with a thin shell). To do this, keep the snail in front of a strong light source so the light shines through it and look at the heartbeat. Have a look at the anatomy section to see where to look for.
Related: 'Diseases' section.

I have an Ampullarius spec. snail. Is this also an apple snail?
Yes, but it's an incorrect generic name, commonly used in the aquarium trade. The correct name for Ampullarius is Pomacea. The genus Pomacea was first described by Perry (1810) and a few months later Montfort described the same genus under the name Ampullarius. So to be correct, the name Pomacea should be used, but there don't seem to be many interactions between the scientific field and the aquarium trade when it comes to the nomenclatura of the apple snail family.
Besides the incorrect use of the generic name Ampullarius, many apple snails are misidentified in the aquarium trade.
Related: 'Species and genera' section.

How long does it take for the eggs to hatch?
The eggs of apple snail hatch between 2 and 4 weeks, depending on the temperature and the species. More info about this subject can be found at the Care section of this site.
Related: 'Care' section and 'Quick guide' section.

Were can I buy apple snails?
Apple snail can be bought in many aquarium and pet shops. Mostly they are sold under names as 'golden snail', 'mystery snail', 'ivory snail', 'Ampullarius australis', 'Ampullarius cuprina' and 'Ampullarius gigas'. Pomacea diffusa and Pomacea canaliculata are the most frequent apple snails in the trade, less common are Pomacea glauca and Pomacea paludosa, other apple snail genera are offered occasionally.
However the possession of and trade in apple snails is not allowed everywhere, this due to the fact and fear of having them released in the wild and facing an apple snail pest. Hawaii and Australia are examples of such regions/countries were you cannot trade/import every apple snail species.
By the way, please don't ask me about apple snail selling shops in your area, I'm not producing a yellow book specialised in snail topics. Best you can do is to check the local fish shops and ask them about these snails. Or try to contact aquarium or pond clubs...

Do apple snail produce eggs during the whole year?
Although apple snails can reproduce during the whole year, there are peak periods in spring and summer. During the winter months however the production rate drops to almost zero.
There are also differences between the species.
Related: 'Care' section and 'Ecology' section.

Do apple snails eat fish or other creatures?
Apple snail aren't very selective when it comes to food and some meat is always welcome to them, but healthy fish are simply to fast for an apple snail to capture and to hold. However, if a fish has died the apple snails will certainly consume the remains quickly, sometimes giving the impression that a fish has disappeared and killed by the snails.
While fish are fast, other snails aren't and it has been described and observed that at least some apple snails predate on other snails.
For example Pomacea canaliculata is know to eat Biomphalaria perigrina (Planorbidae) snails by crushing parts of their shell to expose the softer tissues and Marisa cornuarietis has been observed to eat Bulinus truncatus by putting its proboscis inside its victim's shell. Similar predation practices are described for Pomacea flagellata (on Planorbidae and Lymnaeidae) and Pomacea haustrum (on Planorbidae).
In total absence of food even the cannibalism has been observed, mainly on young snails.
Also beware for eggs of others snails and fish, they are an easy target for a hungry apple snail!

My fish have a disease and I want to treat them. Can those chemicals harm my snails?
The basic principle in combating a fish disease is to use chemical compounds that kill the disease, while having no adverse effects on the fish, due to neurological/metabolistic differences between the organisms.
However, snails have more in common with many parasites then with fish in the way they react to chemical substances. It's thus advised to isolate the snails in a separate tank during treatment of the fish unless you are absolutely sure that the product you use doesn't contain snail-toxic chemicals. And as many disease causing organisms do not survive outside the fish during a few days, together with repeated water changes in the isolation tank, the risk of reinfection through the snail reintroduction can be minimised. Exceptions to this rule are parasites that have a life cycle with snails and fish as intermediate hosts (mainly the case with wild-caught fish/snails). See also here.
A short list with chemicals that are/could be toxic to snails in therapeutic doses:
-Malachite Green (used to treat Ich or white spot, fungi and Velvet or Oodinium).
-Various organophosphorous pesticides like formaldehyde, metriphonate, trichlorphon (= dylox, masoten, metriphonate, neguvon, trichlorophon), dichlorvos and others used to treat infections with flukes, worms, crustaceans and lice.