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| 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 me 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:
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.
'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.
'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.
'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.
'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.
'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.
'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.
'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 bridgesii
snails.
'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.
'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.
'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'.
'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).
'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 25°C, 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 28°C (65-82°F).
It is suspected that at least some apple snail species need an aestivation period in the
mud to avoid burning-out.
'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 28°C
(65-82°F) to stay in good condition.
If the temperatures drops below 10°C (50°F) 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 18°C/65°F in the
winter season.
'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 28°C (65-82°F).
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 bridgesii.
'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.
'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.
'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.
'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 bridgesii
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.
'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.
-metaldehyde used as molluscicide.
-Various copper containing drugs to treat protozoa and fungus infections.
-Parricide D (Di-N-Butyl Tin Oxide) used to eliminate helminthes, acanthocephala,
trematodes, cestoda and worms.
A list of fish phamaceutics of several manufacturers with the active ingredients
is available on http://www.pubnix.net/~spond/product/medicine.html.
Many of the preparation listed here could harm your snails!
'Eradication' section
and 'Diseases' section.
Can I eat my apple snails? And any
suggestions how to prepare them?
Yes, apple snails can be consumed like escargots. They seem to taste somewhat
similar. In fact there are restaurants that serve apple snails and they are
often offered in Oriental markets.
If you are looking for some recipes and tips, click on the link below.
'Eating (apple) snails'
section.
How fast can a snail move?
When creeping over surfaces: Pomacea lineata
(adult): several meters an hour (van Dinther, 1956) and Lanistes nyassanus:
2.8 m per day (Louda and McKaye, 1982). When floating: depending on the water
flow (obvious).
My snail is out of its shell. Will it survive?
Unfortunately the snail won't survive without the shell.
In a normal healthy snail, the body is firmly attached to the shell with the
columellar muscle. When this muscle breaks or becomes detached, the snail can
loose its shell. Such a situation can be considered lethal, as the shell
is vital for the survival of the snail. Without the structural support from
the shell, the mantle cavity collapses
and both the lung as well the gill
function is impaired with suffocation as possible result. Furthermore the shell
protects the weak and vulnerable part of the snail, and without this protection,
the snail becomes and easy and defenceless target for fish and other predators.
Is your snail actually loosens its shell, one should consider to put the snail
asleep. The easiest and one of the more animal friendly methods is to place
the animal in the freezer at 0°C for about 12 hours. Another option is to
completely crush the snail with a heavy stone or hammer. This brutal method
is not for the faint of heart and the freezer method is preferably.
'Diseases' section
and 'Eradication' section.
Are apple snails able reach supersonic speeds?
In general: NO!
However, Carlos from Spain managed to teach his snail how to drive a car. Now his snail
travels at extreme speeds and is able to reach 135 km/h. Unfortunately his last attempt to
establish a new record failed on the French high-way as the snail was unable to reach the
toll-booth.
Is Applesnail.net still maintained?
It is in terms of keeping the webserver up to date, the forum is still moderated and occasionally pages are updated.
Have a look at the author page.
Do you have a question or suggestion?
Please be sure that you question isn't already in the FAQ and don't forget to take a look at the care section before asking things about how to feed/grow/reproduce them and at the ecology section when it comes to how apple snail live their life. Also consider to post a message in the 'Apple snail discussion board' instead of mailing me directly. If you have suggestions, pictures you like to donate, info about a specific species, remarks, corrections or whatever: feel free to contact me!
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