Assassin Snail (Anentome Helena)

Nature's Own Pest Snail Solution

The Assassin Snail (Anentome helena) is the aquarist's most effective biological weapon against pest snail infestations. Striking in appearance with its bold yellow-and-brown banded shell, the Assassin Snail is a predatory freshwater snail that actively hunts and consumes pest snails such as bladder snails, ramshorn snails, and Malaysian trumpet snails. Once introduced, it methodically works through the substrate and tank surfaces, eliminating unwanted snail populations without the need for chemicals or manual removal.

Beyond its pest control role, the Assassin Snail is a fascinating and attractive invertebrate in its own right — slow-moving, peaceful with fish and shrimp, and surprisingly long-lived.

Overview

Pest Control Effectiveness

• Actively hunts and consumes bladder snails, ramshorn snails, and Malaysian trumpet snails
• Works through the substrate to target burrowing snails like MTS
• Most effective when introduced early — before pest snail populations become very large
• For heavy infestations, introduce multiple Assassin Snails for faster control
• Once pest snails are eliminated, they will scavenge on leftover food and protein-based foods

Water Parameters & Tank Setup

• Temperature: 18 – 25°C (64 – 78°F)
• pH: 6.5 – 7.2
• General Hardness (GH): 3 – 10 dGH
• Carbonate Hardness (KH): 1 – 2
• TDS: 100 – 300 ppm
• Substrate: Soft substrate (sand or fine gravel) preferred — they burrow and hunt through the substrate
• Tank Size: Suitable for tanks from 30 L upward

Diet & Feeding

• Primary: Live snails — will actively hunt pest snails in the tank
• Supplement: Sinking protein-based foods such as shrimp pellets, bloodworms, and bottom feeder tablets when snail prey is scarce

Once pest snails are under control, supplement feeding regularly to keep them healthy and active.

Compatibility

• Peaceful with all fish species
• Generally safe with adult dwarf shrimp — too slow to catch healthy, active shrimp
• Will prey on other snail species — do not keep with nerite snails, mystery snails, or other snails you wish to keep
• Can be kept in groups — they will breed slowly in freshwater, laying small individual eggs on hard surfaces

Breeding Note

Assassin Snails will breed in freshwater, but reproduction is slow — they lay single eggs attached to hard surfaces, and juveniles take months to mature. Population growth is gradual and self-regulating, making them one of the few predatory snails that can be kept without concern for overpopulation.

The Assassin Snail is the most elegant and effective solution to pest snail problems — beautiful, fascinating, and endlessly useful in any freshwater aquarium.