Description
The assassin snail is a snail that eats snails. A conical shell with yellow and brown bands, about 2.5 cm long, and a proboscis it pushes in through the opening of its prey's shell. It is sold as biological control for bladder, ramshorn or Malaysian trumpet snail outbreaks, and it works: a small population clears a tank of snails within a few months.
It is worth thinking about what happens next. Once the snails are gone it eats sinking food, meat and leftovers, and survives well. It can also attack snails you want to keep if they are its size or smaller, such as young apple snails.
It breeds in fresh water, but slowly: it lays eggs one at a time and never becomes a pest.
Habitat
It lives in rivers and lakes of Southeast Asia, from Thailand to Indonesia, buried in sand or mud and emerging to hunt. In the aquarium it appreciates a sandy substrate to dig into.
As a predator of snails it must never be released into the wild: where it has been introduced it threatens native snails.
🌊 Water parameters
What about your tank?
Enter your tank's values to see only the compatible species that fit them. Litres apply to fish.
Compatible fish
General guidance based on water parameters, behaviour and known exceptions; always review the individual animals' and aquarium's specific needs.

They share water: pH 7–7.5 and 22–27 °C.

They share water: pH 7–7.5 and 24–28 °C.

They share water: pH 7–8 and 26–28 °C.

They share water: pH 7–7.5 and 22–27 °C.

They share water: pH 7–7.5 and 22–27 °C.

They share water: pH 7–7.5 and 22–27 °C.

They share water: pH 7–7.5 and 24–28 °C.

They share water: pH 7 and 22–28 °C. They only meet at the very edge, so the tank has to hold that value.

They share water: pH 7–7.5 and 25–28 °C.

They share water: pH 7–8 and 24–26 °C.

They share water: pH 7–8 and 22–26 °C.

They share water: pH 7–7.5 and 22–25 °C.

They share water: pH 7–7.5 and 24–28 °C.

They share water: pH 7–7.5 and 22–24 °C.

They share water: pH 7 and 27–28 °C. They only meet at the very edge, so the tank has to hold that value.

They share water: pH 7–7.5 and 24–28 °C.

They share water: pH 7–8 and 22–28 °C.

They share water: pH 7–8 and 22–28 °C.

They share water: pH 7–7.5 and 25–28 °C.

They share water: pH 7–8 and 22–28 °C.

They share water: pH 7–7.5 and 22–28 °C.

They share water: pH 7–7.5 and 24–28 °C.

They share water: pH 7–7.5 and 24–27 °C.

They share water: pH 7 and 24–28 °C. They only meet at the very edge, so the tank has to hold that value.

They share water: pH 7.5–8 and 24–28 °C. They only meet at the very edge, so the tank has to hold that value.

They share water: pH 7.5–8 and 24–28 °C. They only meet at the very edge, so the tank has to hold that value.

They share water: pH 7 and 22–26 °C. They only meet at the very edge, so the tank has to hold that value.

They share water: pH 7–7.2 and 22–26 °C.

They share water: pH 7–7.5 and 22–26 °C.

They share water: pH 7–8 and 22 °C. They only meet at the very edge, so the tank has to hold that value.

They share water: pH 7–8 and 22–24 °C.

They share water: pH 7–8 and 22–27 °C.

They share water: pH 7 and 26–28 °C. They only meet at the very edge, so the tank has to hold that value.

They share water: pH 7 and 22–26 °C. They only meet at the very edge, so the tank has to hold that value.

They share water: pH 7–7.5 and 22–26 °C.

They share water: pH 7 and 23–28 °C. They only meet at the very edge, so the tank has to hold that value.

They share water: pH 7–7.5 and 23–28 °C.

They share water: pH 7–7.5 and 22–26 °C.

They share water: pH 7–7.5 and 23–27 °C.

They share water: pH 7–7.5 and 22–27 °C.

They share water: pH 7–8 and 22–28 °C.
Compatible invertebrates
General guidance based on water parameters, behaviour and known exceptions; always review the individual animals' and aquarium's specific needs.

They share water: pH 7–8 and 22–28 °C.

They share water: pH 7–7.5 and 22–27 °C.

They share water: pH 7–8 and 22–25 °C.

They share water: pH 7.5–8 and 24–28 °C.

They share water: pH 7–8 and 22–28 °C.

They share water: pH 7.5–8 and 26–28 °C.

They share water: pH 7–8 and 22–28 °C.

They share water: pH 7–7.5 and 22–26 °C.

They share water: pH 7–7.5 and 22–27 °C.

They share water: pH 7.5–8 and 27–28 °C.

They share water: pH 7–7.5 and 22–26 °C.

They share water: pH 7–7.5 and 22–26 °C.

They share water: pH 7–7.5 and 22–26 °C.

They share water: pH 7–7.5 and 22–26 °C.

They share water: pH 7–7.5 and 22–26 °C.

They share water: pH 7–7.5 and 22–26 °C.

They share water: pH 7–8 and 22–28 °C.

They share water: pH 7–8 and 22–28 °C.
Sources
- GBIFGBIF Secretariat (2026). GBIF Backbone Taxonomy. Checklist dataset. https://doi.org/10.15468/39omei. Consultado vía GBIF.org, 2026-08. Anentome helena.
Taxonomy verified as ACCEPTED unless stated otherwise.
The care values (pH, temperature and hardness) have no citable source: none of the accepted sources publishes invertebrate profiles. Seriously Fish has none and PlanetCatfish does not respond. A source for invertebrates is still to be agreed.
