Pond Snails
The two familiar forms of pond snails differ in the type of twist they possess. The Lymnaea curls to the left, the Physa to the right.
The pond snails are not dioecious and reproduce by cementing sticky masses of eggs on the plants and glass parts of the aquarium. These eggs are too hard to be eaten by most fish, though cichlids and bettas seem to enjoy them. As they usually reproduce in geometric progression, they are the most prolific snails in the average home tank. A mass of eggs will have hatched in three weeks, and in another three months, these, in turn, will have eggs of their own.
Other types of snails will usually serve the same general purpose but are not so plentiful as the aforementioned.
Care should be exercised to remove all dead snails. They might cloud the water should they be allowed to decompose in the tank. If snails become too plentiful, they may be crushed between the fingers so the fish may clean the meat from the shells. The empty shells may supply a few necessary minerals to the plants.
