Skip to Content

Assassin Snail ‘Anentome helena’: A Detailed Care Guide

Assassin Snail ‘Anentome helena’: A Detailed Care Guide

The assassin snail, otherwise known as Anentome helena, is a unique freshwater snail species that is part of the Nassariidae Family. Despite its name, this snail isn’t typically aggressive.

They are renowned for their pest control capabilities, making them a valuable addition to any aquarium ecosystem. Providing optimal care ensures their well-being and enhances their natural behavior.

This snail species is moderately challenging to care for due to its specific tank requirements and carnivorous diet. You can expect this snail to live for around two years in proper conditions.

The rest of this article will give you an overview, including the care required and tank setup.

Assassin Snail Overview & Origin

  • Common name: Assassin snail or bumblebee snail
  • Scientific name: Anentome helena or Clea helena
  • Family: Nassariidae
  • Care level: Medium
  • Size: 3 inches (7.62 cm)
  • Life Span: About two years
  • Temperament: Solitary
  • Diet: Carnivorous
  • Minimum tank size: Five-gallon
  • Water temperature: 68°F – 75°F (20°C – 22.89°C)
  • Water pH: Between 7.0 and 8.0
  • Water hardness: 2–15 dkH

Originating from Southeast Asia, they have become sought-after additions to aquariums worldwide. As natural predators of pest snails, they offer a non-chemical solution to manage unwanted populations. Their efficient scavenging and hunting instincts make them valuable assets for maintaining a balanced and healthy aquatic environment.

Appearance & Size

If you’ve ever seen one of these snails, you’re probably reminded of bumblebees due to the color of its shell, which coincidentally gives the snail the alternative name “bumblebee snail.” They have yellow and black stripes along their pointed shell, closely resembling a bee.

They generally measure about 3 inches (7.62 cm) in optimal conditions. However, under typical circumstances, they commonly grow to a size of 1.5 to 2 inches (3.81 to 5.08 cm).

Personality & Behavior

Despite the aggressive-sounding name, they aren’t naturally aggressive species. They’re actually solitary creatures, preferring to keep to themselves and hide in the sand. Additionally, you’ll find that they are most active at night.

While assassin snails aren’t naturally aggressive, they keep a carnivorous diet and even eat other, smaller snails.

Average Life Span

If you plan on adding assassin snails to your aquarium, you can expect them to live for around two years. However, due to their unique diet and tank requirements, they don’t always make it to the two-year mark.

With optimal care, however, they frequently surpass the two-year lifespan.

Assassin Snail Care & Tank Setup

Their care level of care is considered medium or moderate, primarily because of their eating habits. You must ensure your assassin snails’ are fed correctly, which means providing them with prey snails or other high-protein food if you don’t have any snails.

Tanks Size

When it comes to the tank size the larger, the better. Assassin snails prefer to live in tanks with larger parameters, mainly because it allows them to adjust to water changes better.

However, these snails need at least a five-gallon tank, but preferably 10 gallons. Anything less than this can negatively impact your snails, as they won’t be able to deal with the water changes.

How Many Are Suitable For a 10-Gallon Tank?

Two assassin snails are suitable for a 10-gallon tank. However, they prefer to live in larger parameters, so if you want to provide the best possible care, it’s better to have a bigger tank. Additionally, these snails will breed on their own, so be wary when housing them together.

When housing these snails, a good rule of thumb to follow is “two snails per 10 gallons.” While you could technically house more together, they prefer to be in bigger spaces.

Water Parameters

  • Water temperature: 68°F – 75°F (20°C – 22.89°C)
  • Water pH: 7.0 – 8.0
  • Water hardness: 2 – 15 dkH

Assassin snails are very particular about the water they live in. So, ensuring the proper water parameters is crucial if you want your snails to live the best lives possible.

Water Temperature

The water temperature is one of the most important things to take into account as these snails don’t deal with water changes very well, which is why a larger tank is ideal. Any drastic changes in water temperature can cause serious injury to the snail.

Therefore, it’s best to keep the water temperature of the tank between 68°F and 75°F (20°C and 22.89°C). Additionally, heat the water before adding them to the tank to reduce shock.

Water pH Levels

The pH levels of the water should be between 7.0 and 8.0. Anything less than 7.0 might be slightly too acidic and can cause their shells to degrade over time.

However, because their shells are very tough, you won’t cause too much damage with slightly acidic water.

Water Hardness

Assassin Snails thrive in moderate water hardness. Aim for a general hardness (GH) level between 2 – 15 dkH. If you don’t have hard water where you live, you can increase the calcium levels in the tank by adding coral or limestone.

Water Current

These freshwater snails prefer a moderate water current. Ensure that the water flow in the aquarium is not too strong, as they thrive in conditions with gentle to moderate currents.

However, a water current isn’t critical to an assassin snail’s care like the pH level and temperature of the water are.

Importance of Calcium

Calcium is the most important mineral you can provide to your snail, no matter the species. Calcium not only encourages proper shell growth that snails need but also helps heal and strengthen damaged shells while promoting healthy egg formation.

While the pH levels in your tank can give you an idea about how much calcium you’re providing your snails, you can also get a testing kit for calcium alone. This is an excellent idea if you only keep snails in your tank.

Tank Requirements

Ensuring the water parameters are met is only the first step to keeping your snails happy and thriving in your care. Proper care also involves adding diverse objects to the tank for their optimal health and thriving.


Assassin snails prefer sand over other substrate options, such as gravel. Sand allows them to hide better and wait for unsuspecting prey. Even in the wild, these snails naturally gravitate toward sandy substrates.

While gravel is still an option you can use, it’s not their favorite.


Decorating an aquarium is one of the most fun aspects of owning one. However, not all decorations should be used for every type of fish or snail.

Luckily, these snails aren’t too picky about decorations in the tank. You can provide any type of decorative object for them to climb on, and they’ll be happy.

Ideal Plants

Assassin snails also aren’t picky about plants because they’re carnivorous creatures. Therefore, they won’t eat any plants you add to the tank — they’re looking for prey snails to eat instead.

Therefore, if you want a planted tank, they are the perfect inhabitants.


Filtering the water in the tank to get rid of any organic matter floating around is ideal for both the snail’s living conditions and the aquarium’s aesthetic look. 

A simple sponge filter will work just fine, as long as the filter can ensure any organic matter isn’t dirtying up the water too much, your snails will be happy.

If you’re looking for a nice sponge filter, I recommend an AQQA Aquarium Sponge Filter.

Assassin Snail Tank Mates

These snails typically get along with most tankmates as long as they are appropriately fed. These freshwater snails like to keep to themselves, so they won’t bother others in the tank.

However, avoiding large loaches or puffer fish is best, as they’re the least compatible with assassin snails. Various shrimp and freshwater clams make great companions.

If you notice your assassin snail attacking other snail species, you’re probably not giving them enough food.

Assassin Snail Food & Diet

Assassin snails are carnivorous, so they only eat meat. They primarily feast on smaller prey snails and use their rasping radula to reach into the shells of these small snails, thus killing and consuming them.

Therefore, you must provide them with enough prey to keep them satisfied and happy.

They have been known to prey on shrimp as well, you can read the article here.

How Often Should You Feed Assassin Snails?

You should feed your snails 1–3 pest snails every few days. The size of the prey you provide your assassin snail with will depend on how much it needs to eat. However, along with eating other snails, they enjoy eating blood worms or fish flakes as long as it’s rich in proteins.

Breeding Assassin Snails

Assassin snails breed very quickly, so whether or not you plan to breed them, beware of this.

Unlike many other snail species, assassin snails are not hermaphrodites, they have distinct male and female sexes.

However, both males and females look exactly the same — it’s impossible to tell them apart. So, if you’re purchasing these snails to breed them, it’s best to purchase a large group and hope you have at least one of each.

Common Health Issues, Treatment, & Prevention

While assassin snails are predatory creatures, they can run into some health issues that you’ll have to be aware of and look out for. The only major health issue you’ll need to be aware of is parasitic infections.

Parasitic Infections

Parasitic Infection Symptoms

If your assassin snail has a parasitic infection, you’ll notice that its shell is starting to form white spots. You also might notice your snail appears motionless on the bottom of the tank for a long period of time, which is unusual, as these snails like to climb.

Parasitic Infection Treatment

Treating parasitic infection in these snails is challenging, as it is with other aquatic life. However, most of the time, you can use copper-based medications to treat parasitic infections. I recommend talking to your local vet or pet store before doing anything that could harm the other tank members.

Additionally, it’s a good idea to quarantine your snails until a solution is reached.

Parasitic Infection Prevention

The best way to prevent parasitic infection in assassin snails is to ensure you’re cleaning the tank regularly. Changing the water and consistently testing the water for ammonia and nitrite levels is crucial.

Additionally, it’s best to pay close attention to the snails to quickly catch any sign of illness.

Assassin Snail FAQs

Can Assassin Snails Overpopulate?

Yes, they can overpopulate aquariums. They breed very quickly, so it’s common to see them begin to overpopulate a tank. This can cause problems within the tank if it’s not taken care of, so be careful with how many you keep together.

Will Assassin Snails Bother Fish?

No, they won’t bother fish. They tend to keep to themselves and only eat a carnivorous diet of pest snails. Therefore, you won’t see them bothering your other fish or any of the plants, which is one reason they make such great additions to an aquarium.

Do Assassin Snails Clean Algae?

Yes, they do clean algae, but not very often. You’ll only see them cleaning algae if they don’t have another food source – pest snails. Therefore, if you want a snail specifically for cleaning algae, the assassin snail isn’t the snail for you.

Do Assassin Snails Eat Gold Inca Snails?

Yes, they do eat Gold Inca snails if they’re small enough. They typically prey on pest snails that are much smaller than them, so if they’re larger than the Gold Inca snail, they might try to eat them. It’s very important to be selective when choosing tank mates.

Wrapping Up

Assassin snails make excellent additions to aquariums if you know how to properly care for them. Many people choose to add them to their aquarium when dealing with many unwanted pest snails.

These snails also make excellent tank mates, so you don’t have to worry about them bothering your other fish or plants. However, for these snails to survive, you must pay close attention to the tank’s water parameters, including temperature, pH level, and hardness.

I’m Elle, the founder of FishHQ. I created this website to share knowledge, tips, and inspiration for beginner hobbyists to help them create a healthy, happy, and vibrant environment for their fish to thrive. Read more...