The Assassin Snail, Clea helena, is a predatory freshwater gastropod native to Southeast Asian rivers and streams. Unlike the vast majority of aquarium snails that graze on algae or detritus, the Assassin Snail hunts and consumes other snails, making it an invaluable biological control agent for aquarists dealing with pest snail infestations. Its distinctive shell bears alternating yellow and brown bands that give it an appearance reminiscent of a bumblebee, earning it occasional comparisons to the popular bee shrimp in terms of visual impact. Assassin Snails are carnivores that track prey using chemoreception, following chemical trails through the substrate to locate and consume snails including Ramshorns, Malaysian Trumpet Snails, Bladder Snails, and other smaller gastropods. They will also scavenge uneaten meaty fish foods, invertebrate pellets, and frozen foods when live snail prey is scarce. Despite their predatory nature toward snails, Assassin Snails are entirely peaceful toward fish and dwarf shrimp, which they lack the speed or ability to catch. They prefer to hunt nocturnally and often bury themselves in soft substrate between feeding activities. Reproduction is slow and controlled — Assassins lay single eggs encased in square capsules and populations build gradually, posing no risk of overpopulation.
