Assassin Snail: Ultimate Guide (Care, Diet, Breeding & More)

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Written By Matt Stevens

Hi, I'm Matt! I've been obsessed with fishkeeping for over 15 years now and created this site to share my knowledge with others.

Assassin Snails over time have become a very popular freshwater snail to own.

Their interesting patterns and easy to look after nature make them a great addition to any enthusiast’s fish tank. Not only this, they’re perfect for keeping populations of other snails in line.

Since they are such amazing freshwater critters, we’ve put together a complete care guide for the Assassin Snail.

Species Overview

Assassin Snail (Anentome Helena), commonly called the bumblebee, is a freshwater snail species from the Nassariidae family. Most of the members of this family are found in South East Asia, most commonly in Malaysia and Thailand.

You may also find these snails in Cambodia and its surrounding areas. Assassin snails are fast-moving as compared to other species.

They are the only predatory aquarium snails used as natural pest control. Besides pests, they can also help clean algae and detritus. Even if you are a beginner-level aquarist, you can easily care for these snails.

It is advisable to have the smallest and slowest snail in your aquarium. Moreover, Assassin snails are community tank compatible and do not attack fish.


Assassin snails have a lifespan of two years on average. However, some of these snails might survive longer if they get the right diet and water conditions.


The Assassin snails are one of the most easily recognizable snails in an aquarium. They have a trumpet shell with brown and yellow stripes, which make it easy to identify them.

They have a light cream color and darker specks spread throughout their body.

Assassin Snail shells.

These Assassin snails have a complete Proboscis and two tentacles with eyes near the base that allow them to navigate through the waters.

You may find 8 whorls (with three bands each) on their shells with lateral ridges. The operculum is the most interesting part of the shell that acts like a trapdoor and shuts it off when the Assassin snail hides inside.

You can also view the operculum to see if an Assassin snail is dead or alive since dead snails cannot move their trap doors. Above the snail’s head, there is a foldable tubular siphon protruding from the shell’s tip, which has a chemoreceptor.

You might have seen this chemoreceptor in other species that have predator or scavenger characteristics. The receptors help the snail navigate through the waters and detect the movement of potential prey at a distance effectively.

Assassin snails use their long proboscis to catch the prey and pierce its body using their sharp radula (a saw-like tongue).

The siphon serves as a versatile water sampling extension. The Assassin snail can also use this part as a snorkel when it is buried or underwater. The muscular foot inside the shell helps the snail to move forward via muscle contractions.

It also helps in burrowing, storing, and catching food, etc.


The Assassin snails have an average size ranging 2.5 – 3 cm (1 inch) depending on their age and the kind of conditions they live in. These snails rarely grow up to 2 cm or more, but you can keep them in the aquarium despite their small size.

For instance, these snails are excellent hunters for pests, which is why you won’t need to use harmful chemicals in the water. Let us now take a look at the tips to care for Assassin snails and the important factors related to them.

Understanding the basics will make it easier for you to keep these snails in a tank of any size.

Assassin Snail Care

One of the best things about Assassin snails is that they do not require extensive care. You do not have to worry about them as long as you provide them with the right water conditions and plenty of food to survive.

Picture of a Assassin Snail (Anentome helena).

Tank size and stability are the two main factors in Assassin snail care. For starters, try and put the snails into the water tank very gently so that you do not harm/damage them.

Let us discuss some other important factors, including water parameters, for keeping Assassin snails.

Tank Size

Choosing the right tank size is essential to your Assassin snail survival. Ideally, a tank with a 30-gallon volume is ideal if you wish to provide sustainable conditions.

Keep in mind that larger tanks have a better capacity to adapt to water changes better as compared to smaller ones. Although these Assassin snails do not escape in most cases, you should still try and keep the tank covered as much as possible.

Similarly, frequently check water quality and the population of freshwater snails that Assassin snails feed on the capacity of the tank.

You should also keep the growth ratios of these snails in mind when you choose the tank size, as bigger snails will need more tank space and better water quality to survive.

You can find these snails in a group of 5-6 and have a direct impact on water quality and maintenance. All you should know is that smaller tanks are just not the best long-term options for Assassin snails.

Water Parameters                   

Heating and Filtration

Heating and filtration checks are an absolute must if you are looking for water parameter guidance. These snails do not like changes in their water conditions and need stability to grow efficiently.

The right temperature for the growth of these snails ranges between 24 and 28 C or (75 and 82F). You should pay specific attention to this if you are planning to breed them soon.

Low temperature slows down the snail’s metabolism, which is why they go underground until the temperature is back within the normal range.

Assassin Snails on plant.

Tank Cycles

We suggest that you ensure that your tank fully cycles (all the nitrites convert into nitrates in the tank since ammonia and nitrites can be harmful to marine life).

You should always keep the nitrite and ammonia levels at 0 ppm by changing the water partially on a regular basis.

Fertilizers and medications can have a profound effect on the quality of water, so ensure adding them in a balanced amount if you want to provide clean water for your assassin snails.

Most Assassin Snails are sensitive to water conditions, and it can hinder or block their growth completely. For example, copper is lethal for these snails and can kill them. So, you should always add medications and fertilizers that are snail and shrimp safe.

pH Levels

Keep the pH levels between 7.0 and 8.0 with minimal to high levels of KH and GH levels. These KH and GH levels usually range between 8 and 20, so the water should not be too soft or too acidic. The imbalance can deteriorate the Assassin snail’s shell.

These seashells consist of 90-95 percent calcium carbonate, and low pH levels can dissolve them and leave the snails prone to damage and external threats.

Most Assassin snails can survive in water with a pH as low as 6.5, but you should still not keep the snail in acidic water as it might dissolve the shell over time.

What to Put In the Tank?

It is important to pay attention to the partners you add to their tank as Assassin Snails are carnivores. They are quite friendly and open with other species of their kind.

Try adding plant life for a better aesthetic look and development of these Assassin snails. Although the snails do not eat these plants, they can still use these plants to move around the water tank.

Common Diseases

Most Assassin snails are easy to care for, but they are at risk of diseases. For example, one of the signs of disease is white spots on the snail shell.

These white spots indicate the presence of parasites that may harm the snail if you do not treat them. These parasites can also weaken the snail shell.

Poor water quality can lead to several health complications for the snails, so clean their tanks every 1-2 weeks to provide a better atmosphere.

What Do Assassin Snails Eat?

Assassin snails are carnivores that bury themselves into the ground until they find something to eat. They usually feast on other smaller snails and insects and do not change this habit in captivity. They are hunters and usually find their food themselves.

Assassin Snail eating

However, natural prey isn’t enough if they are in a tank. You should look for snail feed and blood worms if your water tank does not have enough food.

Place these blood worms on the bottom of the tank, and the Assassin snail will do the rest to eat them. You need to feed them twice a day. As an FYI, they usually come out to hunt during nighttime.

Snail pellets and snail flakes are other great options that you can opt for if you need more food for the snails. Things like water fleas or brine shrimp are also amazing sources of protein to ensure your snails grow well.

Consider giving the snails a calcium boost since it will strengthen their shells and improve their life expectancy. Crushed snail and clamshells are also great calcium supplements that you can easily find.

Lastly, you can also feed these Assassin snails algae as they love to munch on them.

Behavior & Temperament

Assassin snails are quite peaceful despite being predators. They do not approach preys that are too big or too fast for them to catch.

These snails hunt during the night and wait underground during the day until the conditions turn suitable. They usually extend their long siphons to catch their prey and detect light and vibrations around them with their stalks.

Assassins do not require a high amount of light and still detect sudden movements underwater. You might also find these snails climbing on glass decorations in the tank, but they never drift too far from the ground level.

See some Assassin snails in action below.

Assassin Snail Tank Mates

Assassins get along with most of their species quite well. These snails fit with scavenger breeds like the Cory Catfish and other delicate fish breeds like the Otocinclus Catfish perfectly.

Small-sized clams like Asian Gold Clams are also a great option. You can also go for other unique breeds like Viper Shrimp, Ghost Shrimp, and others.

However, it is still important to add larger fresh shrimps and ensure that your Assassin snails have their bellies full. Rough marine life like catfish or goldfish isn’t a suitable pick to become an Assassin’s tank mate.


Assassin snails have gonochoristic systems, and they fertilize internally. This means a male and a female are necessary for these snails to reproduce.

You cannot distinguish between a male and female Assassin snail by their outer appearance, which is why you should keep them in groups of 4-5 snails to ensure you have both sexes within the group.

The male Anentome Helena usually gets on top of the female and holds the position for at least 20-30 minutes. The male then slides to the right and transfers the semen into the female.

The female then releases 1-4 egg capsules in a line, with a distance of almost 5 mm in between them. The eggs have a length and size of 3-4 mm on average. The breeding temperature needs to stay above 20 C or the snails won’t breed.

Newly born snails are usually 3-4 mm and have the same color as adults. However, some of these snails may not have stripes on them. These snails grow their shells in 2-3 months and have a similar diet as their parents.

These baby snails have high survival rates, sustenance chances, and growth ratios.

Assasin Snail – Final Thoughts

Assassin Snail is a member of the mollusks family and a wonder for those who love marine life.

It is one of the best species to add to your aquarium and can help add more vibrancy to it.

Pay attention to providing your snail with the right conditions to grow and live. Make sure you study more about the Assassin snail before you get yourself one.