Snails are nearly ubiquitous in freshwater aquaria. Aquarists vary in their attitude towards snails - many see them as a scourge that must be controlled, if not eliminated outright. Bulletin boards are full of questions about how to control snail populations. Snails are easily introduced on plants, rocks or other decorative items like driftwood. Most reproduce quickly and some, like Malaysian Trumpet Snails, quickly grow to the level of infestation. Some snails eat plants, and can damage aquarium plants. Some will eat eggs, even baby fish. And some play a role in the life cycle of fish pathogens.
Many aquarists seem snails in a more positive light. Snails consume algae and can keep glass and rocks clean. Snails consume dead plant parts and uneaten food that might otherwise decompose and foul the water. Trumpet snails burrow through the substrate and bring oxygen into these substrates.
Quite apart from this utilitarian view of snails, some aquarists see them as desirable pets, and may dedicate aquaria to certain species. Popular pets include Olive Nerita snails, Ramshorn snails and Apple snails (also known as Mystery snails). [Read the rest of my post at HubPages.com]