Assassin Snail

Assassin Snails (Clea helena) have become a popular freshwater snail to keep in the aquarium hobby. They have a reputation of being able to help keep populations of some other freshwater snails, such as trumpet, pond, bladder, and ramshorns snails in check. They eat all other types of snails that are their size or smaller, but they will not harm snails that are larger (such as Mystery Snails, Giant Sulawesi Snails, and larger Nerite Snails).  However, large groups of Assassin Snails have been known to gang up on a larger snail and take it down, so caution should be exercised when keeping these, even with larger snails.  They are safe to keep with fish, most invertebrates, live plants, and other aquarium inhabitants because their preferred meal is snails.