Descripción
The Malaysian trumpet snail has a conical, elongated shell like an ice cream cone, and spends the day buried in the substrate, coming out at night. If you have a sand-bottomed tank and have ever seen the floor move, that is them.
And that behaviour, which at first looks like a quirk, is precisely its value. By burrowing constantly they turn the sand over and stop it compacting. In a tank with fine substrate and nothing to disturb it, anaerobic pockets form — oxygen-free zones where sulphides build up; when they rupture they release gas into the water and can cause serious problems. Trumpet snails prevent that with no effort from you, and they reach places your gravel vacuum never will.
They reproduce by parthenogenesis. This matters and should be said before anyone introduces one: a single individual is enough to found an entire population, with no mate needed. There is no realistic way to keep just a few.
Think it through before adding them, because eradicating them afterwards is practically impossible: they live buried, so they cannot be picked out by hand and traps do not reach them. That said, most keepers who have them would not want them gone.
As an indicator: they live hidden, so if you start seeing many by day and on the glass, it signals excess organic matter on the bottom or a lack of oxygen down there. It is a useful warning.
Hábitat
Melanoides tuberculata is native to Africa and southern Asia, where it inhabits rivers and lakes with soft bottoms it can burrow into. It has now spread across much of the world and is considered invasive in several regions.
Its main requirement in the aquarium is straightforward: fine-grained substrate, ideally sand. Over coarse gravel it cannot bury itself, which is what it does best, and it loses both its natural behaviour and all its usefulness. A trumpet snail in a gravel tank is just another snail.
Like all snails it needs hard water. And here the symptom is especially characteristic: in acidic water the shell tip corrodes away, leaving the apex blunt and holed. If you see your trumpet snails with eaten tips, your water is too acidic or too soft for them, and probably for any other snail you keep.
It tolerates temperature very well, from 20 to nearly 30 degrees, and copes with low oxygen levels other snails cannot. All told, it is one of the hardiest invertebrates you can keep.