The Assassin Snail, also known as Clea helena, is a freshwater snail species that is popular among aquarium enthusiasts. It is native to Southeast Asia, particularly in Thailand, Malaysia, and Indonesia.

As its name suggests, the Assassin Snail is a carnivorous species that feeds primarily on other snails, including pest snails that can overrun an aquarium. It has a cone-shaped shell that is typically yellow or brown in color, with a darker stripe running along the length of the shell.

Assassin Snails are relatively easy to care for and are a popular choice for controlling snail populations in aquariums. They prefer well-oxygenated water with good water flow, and can tolerate a range of water conditions. They are best kept in small groups, but should not be kept with other snail species or small shrimp, as they will prey on them.

In terms of diet, Assassin Snails should be provided with a varied diet that includes snails, sinking pellets, and frozen or live foods. They will also consume dead plant matter and detritus in the aquarium.

While Assassin Snails can be effective at controlling snail populations, it is important to note that they will not eliminate all snails from an aquarium. Additionally, if the snail population is too large, it may be a sign of an underlying issue in the aquarium, such as overfeeding or poor water quality.