Assassin Snail

Clea helena

Invertebrates

A highly effective and popular carnivorous freshwater snail used primarily for pest snail control. They actively hunt and consume smaller snails like bladder, ramshorn, and pond snails. Featuring a striking yellow and dark brown spiraled shell, they are a functional and attractive addition to aquariums. Unlike many aquatic snails, they are not hermaphroditic and reproduce quite slowly.

At a Glance

Adult Size2.5 cm
Body ShapeGlobular
Growth RateSlow
TemperamentPeaceful
Water TypeFreshwater Only
Flow PreferenceLow
Waste OutputLow
StockingSolo or group

Tank Requirements

Minimum Volume10 L
Minimum Length20 cm
FlowLow
Water TypeFreshwater Only
Must-Haves in the Tank
Sand (Sifters)

Water Parameters

Temperature2228°C
pH78
Hardness815 dGH

Temperament & Compatibility

Aggression LevelPeaceful
2/10
Where They Swim
Surface
Mid-level
Bottom
Stocking Guidelines
Keep at Least1 (solo is fine)
Max per TankNo limit
Can Live Alone?Yes
Behavior Traits
Nano / Bite-sized (Predation Risk)Snail EaterDigger (Disturbs Substrate)

Available Varieties

Each variety inherits the species defaults above. Only differences are highlighted.

Standard

The standard Assassin Snail form found in the aquarium trade. They spend much of their time buried in sandy substrates, waiting to ambush passing pest snails.

Same care requirements as the base species

Also known as: Common Assassin Snail

Assassin Snail Care Guide Summary

The Assassin Snail, scientifically known as Clea helena, belongs to the Invertebrates family group. Adults reach a maximum size of approximately 2.5 cm and have a globular body shape with a slow growth rate. Classified as peaceful, this species primarily occupies the bottom zone of the aquarium and produces a low level of biological waste.

To thrive, the Assassin Snail requires a freshwater only aquarium with a minimum volume of 10 litres and a tank length of at least 20 cm. Water temperature should be maintained between 22°C and 28°C, with a pH range of 78 and a general hardness of 815 dGH. A low water flow is preferred.

The Assassin Snail is a rewarding species to keep, provided its core environmental needs are met. The Assassin Snail is typically available in one standard form.

Assassin Snail Habitat Setup

When setting up an aquarium for the Assassin Snail, a low water flow best suits their natural preferences. Because this species occupies the bottom zone, the aquarium layout should prioritise sufficient floor space with hiding spots among rocks, wood, or dense planting. Useful additions include a sand substrate to accommodate their sifting behaviour. Keepers should note that expect substrate disturbance, so lightweight décor should be secured.

Assassin Snail Compatibility Notes

Classified as peaceful, the Assassin Snail is adaptable and can be kept singly or in a small group, offering flexibility when planning a community tank. When choosing tankmates, snails will be treated as food rather than tankmates. Selecting tankmates that favour different water layers from the bottom zone can help reduce competition and territorial overlap.

Frequently Asked Questions About Assassin Snail

How big does Assassin Snail get?+
Assassin Snail (Clea helena) typically reaches a maximum adult size of approximately 2.5 cm. They have a globular body shape and a slow growth rate.
What tank size does Assassin Snail need?+
A minimum aquarium volume of 10 litres and a tank length of at least 20 cm are recommended for Assassin Snail. This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Assassin Snail need?+
Assassin Snail thrives in freshwater only conditions with a temperature range of 22–28°C, a pH between 7 and 8, and a general hardness of 8–15 dGH. A low water flow is preferred.
Is Assassin Snail peaceful or aggressive?+
Assassin Snail is classified as peaceful with an aggression score of 2 out of 10. They are generally well-suited to peaceful community tanks.
Can Assassin Snail live alone?+
Yes, Assassin Snail can be kept singly or in a group. They are flexible and adapt well to both setups.
Will Assassin Snail eat snails?+
Yes. Assassin Snail actively feeds on snails. While this can be useful for controlling pest snail populations, it means decorative snails should not be housed with this species.
Does Assassin Snail have any special tank requirements?+
Yes. Assassin Snail benefits from sand (sifters) in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.

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