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
Tank Requirements
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Water Parameters
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Temperament & Compatibility
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
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🟢Ideal Tank MatesAssassin 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 7–8 and a general hardness of 8–15 dGH. A low water flow is preferred. An aquarium test kit can help you monitor these values.
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. Browse aquarium sand substrate options to find the best fit.
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.
Recommended Tank Sizes
Standard aquarium sizes that meet the minimum volume and length requirements for Assassin Snail.
5 Gallon
10 Gallon Standard
15 Gallon Standard
20 Gallon High
20 Gallon Long
29 Gallon Standard
Show 27 more tank sizes
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.
Similar Species
Bladder Snail (Pest Snail)
Physella acuta
A tiny, fast-moving freshwater snail almost universally introduced accidentally via live aquarium plants. While frequently labeled a 'pest' due to their rapid, prolific reproduction, they are actually an excellent cleanup crew. They consume algae, uneaten food, and decaying plant matter without harming healthy plants. They are hermaphroditic and can self-fertilize, meaning a single snail can start a massive colony.
Mystery Snail
Pomacea bridgesii
A large, popular, and active freshwater snail. Unlike other apple snails, they generally do not eat live, healthy plants, preferring algae, detritus, and sinking foods. They require calcium-rich, alkaline water to prevent shell erosion. Females will frequently leave the water to lay distinct pink egg clutches above the waterline.
Nerite Snail
Neritina natalensis
The gold standard for algae control in freshwater aquariums. Native to Africa, these snails are renowned for their voracious appetite for diatoms and spot algae. A key feature is their inability to breed in freshwater; they lay white sesame-seed-like eggs that will not hatch without brackish/marine conditions, preventing population explosions. They are escapists and require a tight-fitting lid.
Clown Loach
Chromobotia macracanthus
A highly popular but large-growing shoaling fish famous for eating nuisance snails. Known for their striking orange and black bands, they are highly social and must be kept in groups. They have no standard scales, making them sensitive to medications and prone to Ich, requiring pristine, warm water. They are known for their quirky behavior of sleeping on their sides or backs.
Ramshorn Snail
Planorbidae fam.
Ramshorn snails are highly adaptable, peaceful invertebrates named for their shells, which resemble a coiled ram's horn. They are excellent clean-up crew members that consume detritus, uneaten food, and soft algae without harming healthy plants. Because they are hermaphroditic and can self-fertilize, they breed prolifically if an aquarium is overfed.
Malaysian Trumpet Snail (MTS)
Melanoides tuberculata
The Malaysian Trumpet Snail is a highly beneficial, albeit prolific, freshwater invertebrate. They are famous for burrowing deep into the substrate during the day, which prevents toxic anaerobic gas pockets and aerates plant roots. They emerge at night to scavenge for detritus, algae, and uneaten food. They reproduce via parthenogenesis, meaning a single snail can quickly clone itself to start a colony.