SNAILS AND DISCUS FISH
By Jim E. Quarles
Every now and then a very interesting question is asked by someone new
to the discus hobby. And you some times notice these questions in the
I found this one in a very strange place. But it is interesting and
since I know a little about apple snails I thought I would answer it here.
I love interesting subjects and questions. I rarely reply to the more
fundamental stuff like I have fish should I keep them in water!! Ha ha ha.
You generally can get those answers from T.F.H books or off the Internet.
Apple snails or Pomacea, canaliculata. Are found all over the world
now, and are imported in great numbers by the aquarium hobby. They are
also used as food in the far east. They are even eaten raw..Yak. In a lot
of places where they have been introduced such as Hawaii, and parts of
Asia they have become pests much like the rabbits were when introduced to
Australia. Once again it just proves that introducing any species to a new
habitat is not to be taken lightly.
WHERE DO SNAILS FIT IN?
The phylum Mollusca, includes all those animals commonly referred to
and known as snails, slugs, nudibranchs, oysters, clams, octopuses, and
squids. So you can quickly see Mollusca contains a lot of different
But since we're interested in Apple snails and if you are considering
having them in your discus tanks, there are a few things you should be
Many of the freshwater snails are intermediate hosts for different
kinds of parasites. It has been reported that over 200 million people in
America and Asia along with Africa are infected every year with parasites
that need the snails to complete their life cycles.
Other factors need to be considered as well. Snails require a great
deal of green plants or prepared substances for food. If not fed properly
they will attack and eat almost any plant in the tank with them.
And of course being such heavy eaters they also produce a lot of waste
into the water. This sometimes will over load the filtering system in use.
Keeping apple snails in water warm enough for discus is no problem.
They come from areas where the water can reach up to 100 degrees F.
While it is unlikely that you will find a problem with transmitted
parasites in the closed system of an indoor aquarium, using new snails
collected out of doors can present this problem. Only snails produced by
breeders indoors away from birds and other snail are free of this
The keeping of apple snails is a interesting endeavor as a hobby, but I
would not recommend that they be kept with discus or other fish of value.
The life cycle and breeding habits of apple snails can offer hours of
fun and has a certain educational value in and of itself.
The use of indoor ponds are almost always required to obtain any kind
of breeding success of apple snails. They can and will live in small
aquariums for up to two to three years. But it will indeed be rare that a
good successful spawning will occur in such a setup.
Breeding of Apple Snails
Apple snails are able to breath via the water transport of oxygen much
the same as fish, but they can also breath air direct via a tube extended
out of the surface of the water. Oviparous snail such as the apple snail
usually lay eggs in clusters which are incased in a jelly like substance
above the water line.
When the young snail hatch out they simply fall into the water below
and start eating. And boy can they eat!
In most cases the snails are not active all the time in nature. They
spend up to three or four months a year in a rest cycle barely alive deep
in a mud cave. This seems to be required for successful spawning on a
regular bases. In the home aquarium this is not possible.
One other factor needs to be considered if you plan to place them with
discus. Discus do better in a acidic environment, while snails fare much
better in a pH above 7.0, in fact, keeping them in acidic conditions will
tend to desolve the shell of the snail and weaken it.
Most hobbyist think of the Golden apple snail, but that is a fairly
recent hybrid of the many other colored apple snails. However it is the
one most often offered for sale in the pet store. It is the Pomacea,
I personally have kept apple snails, giant snails and without meaning
to do so rams-horn snails. I found them interesting in and of themselves.
But I would never consider them for use in a discus tank.
Recommeded reading " Apple Snails T.F.H. Ts-260 by Dr.Gloria
Perera and Jerry G Walls."