Malaysian Trumpet snail
This, not longer than 3 cm, snail is the best snail edition to a planted tank especially! They will eat algae, dead plant material, leftover food and will not eat your plants. The main reason they are kept in planted tanks is for their ability to aerate the gravel since they spend most of their time digging through the substrate. They will come out of the gravel at night. If you are concerned that your snails are gone or dead, please try to focus on the gravel surface for a while and you will see at certain places that your gravel is moving. That's the snail digging its way through. All snails need alkaline waters to rebuild their shells. Loaches and Cichlids will eat snails. This snail is a good indicator for bad water quality. If something is wrong they will all head up towards the surface over the aquarium glass.
Photo by Dusko Bojic