Snails in the aquarium: are they useful or harmful?

Are snails in the aquarium useful or harmful? Sooner or later every aquarist finds himself facing the problem of the proliferation of snails in his aquarium.

Snails in the aquarium

First of all, I would like to dispel the belief that introducing loaches into the aquarium can definitively solve the problem of weedy snails, in fact, not all species feed on snails and often do so only when they are young.

Furthermore, the choice almost always falls on the widespread thrombotic macracanthus (better known as clown loach) which, despite being a very beautiful and particular fish, is decidedly cumbersome and lively, needs to live in a group with its own kind and as an adult it reaches such dimensions ( around 30 cm.) which should discourage the purchase for tanks of less than 300 litres.

Another species that feeds on snails is the puffer fish genus, but even in this case these are not fish to buy lightly, since they have special needs, some, such as the tetraodon biocellatus, need to live in brackish water; they are generally peaceful when young but territorial and/or aggressive in adulthood.

Consequently, the too hasty introduction of these fish into unsuitable tanks, for the sole purpose of eradicating the unwanted snails, brings more disadvantages than advantages (from the pan into the fire).

Chromobotia macracanthus

The second urban legend is that all snails devour plants, in fact, most of them are detritivorous, i.e. they feed on the debris (food remains) that accumulate on the bottom of the aquarium, on the furnishings and on the plants, as well as some types of algae, diseased or decaying leaves and helps keep the walls of the tank clean.

Of course, these are very slow and often tiny animals, so they need a lot of time to complete the cleaning job, but patience is the virtue of the strong and we cannot expect to delegate the complete cleaning of the windows to snails or phytophagous fish, consequently, the bulk of the work is up to us, periodically, with the help of the classic magnets or a simple way of filtering wadding (person wool).

However, if the leaves of your plants are damaged, wait to point your finger at the snails, the culprit could be someone else, for example, the beloved ancistrus.

Among the most common gastropod species that actually damage plants, we find:

Marisa cornuarietis

Peaceful and breedable similar to the apple genus (but does not come out of the water), it feeds on any food of vegetable origin as well as algae and detritus;
its introduction into planted tanks is not recommended because it seems to be able to eat leathery plants such as Anubis and microform.

Lymnaea stagnalis

Robust and adaptable, in nature, it lives in stagnant waters or with weak currents, it nourishes aquatic plants and salad leaves;
not to be confused with the species physa, rather similar,
but from which it differs due to the more elongated and pointed terminal part of the shell.

In my opinion, snails are interesting, useful creatures and some species are very beautiful to look at, either due to the round shape of the shell of the species called “apple snails”, or due to the bright colours or the suggestive pigmentation of the shell like that of the physa.

To keep the general population under control, it is sufficient to maintain correct management of the tank, which can be summarized in three simple rules which will also prevent you from falling into other very common mistakes:

– few fish and many plants
– regular partial changes and not too spaced
– controlled administration of food

this last point is fundamental given that proliferation is closely linked to the excess of food they have available.

Elizabeth Canales is fond of marine life since childhood and got an aquarium as a gift from her father on her 6th birthday. Since then she started to take care of Coralia (her goldfish). Her love for fish made receive her B.S. in Marine Biology from the University of Washington and DVM from Delaware State University.

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