Assassin Snails: The Efficient Aquarium Cleaners

Fact Checked by
Sheldon Myers, MS / Aquarist


Have you ever had trouble with pesky snails overpopulating your aquarium? If so, then Assassin Snails might just be the solution you’re looking for! These carnivorous, freshwater snails are known for their ability to hunt and control other snail populations. In this article, we’ll explore everything you need to know about Assassin Snails, including their habitat, appearance, diet, tank setup, breeding, and tank mates.

Habitat & Origin

Assassin Snails, also known by their scientific name Clea helena, are native to Southeast Asia, particularly in countries such as Thailand, Malaysia, and Indonesia. They thrive in slow-moving rivers and streams, as well as freshwater ponds and lakes.



Assassin Snails have a striking appearance. Their shells are cone-shaped, reaching up to 1 inch in length when fully grown. They display a beautiful pattern of alternating dark brown and yellow stripes that run diagonally across the shell.


The body of an Assassin Snail is quite unique, with a cream-colored foot and a darker head. They have a siphon, a tube-like extension, that allows them to breathe air while buried in the substrate.


Preferred Prey

Assassin Snails are carnivorous and primarily feed on other snails, making them excellent aquarium cleaners. They prefer smaller snails like Ramshorn and Malaysian Trumpet Snails but will also eat decaying plant matter and fish food if necessary.

Feeding Habits

These snails are nocturnal hunters, meaning they’re most active during the night. They use their siphon to detect the scent of nearby snails and then attack them, injecting venom to immobilize their prey before consuming them.

Tank Setup

assassin snail
assassin snail

Tank Size

A 10-gallon tank is usually sufficient for a small group of Assassin Snails. However, if you plan to keep them with other fish, a larger tank may be necessary to provide ample space for everyone.


A soft, sandy substrate is ideal for Assassin Snails, as it allows them to burrow and hunt for prey easily. Avoid using sharp or rough substrates, which can damage their delicate bodies.

Decorations & Hiding Spots

Assassin Snails appreciate having hiding spots and areas to explore in their tank. Adding live plants, driftwood, and caves will not only make your aquarium more visually appealing but will also provide your snails with the shelter and hunting grounds they need.

Water Parameters


Assassin Snails thrive in water temperatures ranging from 70°F to 80°F (21°C to 27°C). Maintaining a stable temperature within this range is essential for their well-being.


These snails prefer slightly acidic to neutral water conditions, with a pH level between 6.5 and 7.5. Consistent water parameters are crucial for their health, so be sure to monitor and adjust as needed.


assassin snail
assassin snail

Mating Process

Assassin Snails are not hermaphroditic, meaning they require a male and a female for reproduction. They mate by coupling together, and the male transfers sperm to the female to fertilize her eggs.

Egg-laying & Hatching

Females lay individual eggs, each encased in a protective capsule, on solid surfaces like aquarium glass or decorations. The eggs are yellowish-brown and typically take 3-4 weeks to hatch. Once hatched, the baby snails will burrow into the substrate and begin their lives as tiny predators.

Tank Mates

Compatible Tank Mates

Assassin Snails can coexist with various tank mates, including small, peaceful fish such as tetras, rasboras, and guppies. They can also live alongside shrimp, as long as they have plenty of snails to feed on.

Incompatible Tank Mates

Avoid keeping Assassin Snails with larger, aggressive fish that may prey on them or disturb their habitat. Similarly, it’s not a good idea to house them with snails you want to keep, as they will eventually become the Assassin Snails’ prey.


Assassin Snails are fascinating creatures that make a great addition to any freshwater aquarium. Not only do they help control unwanted snail populations, but they also add a unique element of intrigue to your tank. With proper care, tank setup, and compatible tank mates, these efficient hunters will thrive and keep your aquarium clean.


  1. How long do Assassin Snails live? Assassin Snails can live up to 3 years when provided with proper care and a suitable environment.
  2. How many Assassin Snails should I add to my tank? It’s best to start with a small group of 3-5 snails to ensure they have enough food sources. Be cautious about adding too many, as they may deplete their food source.
  3. Will Assassin Snails eat all the snails in my aquarium? While Assassin Snails are efficient hunters, it’s unlikely they will eradicate every single snail in your tank. However, they will help control the population.
  4. Do I need to supplement my Assassin Snails’ diet? If there’s a shortage of snails in your aquarium, you can provide them with sinking pellets, frozen bloodworms, or other protein-rich foods.
  5. How do I prevent Assassin Snails from breeding in my tank? If you want to control their population, you can simply remove the egg capsules as you see them. However, their breeding rate is relatively slow, so it’s unlikely you’ll have an overpopulation issue.
Elliot Galindo
Elliot Galindo
Elliot Galindo is a highly educated expert on freshwater shrimp and their care as pets. He received his Bachelor's degree in marine biology from the University of Oregon and has used that knowledge to become an authority on shrimp care.



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