Assassin Snail

Anentome helena

Also known as: Killer snail, Bumblebee snail

Water Parameters

• Temperature: 22–27°C
• pH: 7–8
• Hardness: 143–268 ppm

Care Summary

A specialised carnivorous snail used primarily as biological pest control rather than as a centrepiece species. Buries in the substrate during the day and emerges at night to hunt. Will completely clear a pest snail outbreak within weeks, then need to be removed or fed bloodworms and other meaty foods to survive. Slow-moving and unobtrusive — many keepers forget they're in the tank between sightings. Available in distinctive yellow-and-black banded shells. Note: actually slow predators despite the name; they hunt by burrowing under prey rather than chasing.

Tankmates

A specialist predator that hunts other snails — particularly useful for clearing pest snail outbreaks (bladder snails, ramshorn snails, Malaysian trumpet snails) that often arrive on plants. Will also attack and kill other 'good' snails like nerites and mystery snails, so cannot be kept alongside any other snail species. Will attack and eat small shrimp, particularly during moulting when they're vulnerable. Peaceful toward fish and ignores them entirely. Should NOT be added to tanks with deliberate snail or shrimp populations unless those populations are being explicitly removed.

Compatible with

• Betta
• Neon Tetra
• Bronze Corydoras
• Guppy
• Platy
• Harlequin Rasbora

Avoid keeping with

• Mystery Snail
• Nerite Snail
• Cherry Shrimp
• Amano Shrimp
• Any Snail Species
• Any Shrimp Species

Common Problems

• starvation after clearing all pest snails (need to be fed protein)
• predation on desired snail and shrimp populations
• burrowing under substrate makes them hard to find
• slow population growth compared to pest snails they hunt

Sources: seriouslyfish.com, fishbase.org · Last updated: 2026-06-06