Assassin Snails: What And How Do They Kill? (A Complete Guide!)

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Assassin snails are well-known in the hobby for killing the pest snails in the aquarium. But can they kill other snails, fish, or shrimp?

And unlike other animals, snails have a very peculiar body shape and structure. That further makes us curious about how assassin snails kill their prey. 

In this guide, I will give you a complete explanation of what and how assassin snails kill. So make sure to read till the end!

Anatomy of Assassin Snails:

Before we understand what and how the assassin snails kill, we must learn some essential terminologies about their anatomy.

ShellCone-shaped, brown, and yellow striped. They are also referred to as bumblebee snails because their shells kind of resemble bumblebees.
SiphonA tube coming out from the shell, which they use to breathe. These snails use the siphon as a snorkel (breathing tube) when they are buried. Remember that these snails don’t breathe air like most other aquarium snails.
EyesHeads of assassin snails have mobile and partially retractable tentacles where the eyes are located near the base region.
FootAssassin snails have a relatively thin and translucent muscular foot which they use during burrowing, climbing, and capturing food.
OperculumThe assassin snail’s body structure also consists of a part called operculum (the trapdoor), which closes the shell when it is in danger.
ProboscisIs a structure they use to suck their prey bodies. And even if their prey snails have a trapdoor, the assassin snails can use their proboscis to peel open the trapdoor of other snails. You could often find the assassin snails exploring around the tank and hunting for food with their proboscis extended.

Related Read: Can Assassin Snails Live Out Of Water?

What Snails Do Assassin Snails Kill?

In short, there are no safe snails that can be kept with assassin snails because, whether big or small, with or without operculum, these snails will eventually attack any type of snail. They are opportunistic carnivores and active predators of snails.

Do Assassin Snails Eat Mystery Snails? Usually, Assassin snails are known to eat pest snails. However, at times if they get interested, they can even gang up together to attack larger snails like a mystery snail.

Do Assassin Snails Eat Nerite Snails? As a general rule, assassin snails can also attack the nerite snails. If there is the absence of adequate small snails or food for the assassin snails, they can get triggered to attack the nerite snails.

Read: How Many Nerite Snails Per Gallon?

Will Assassin Snails Eat Each Other? In general, assassin snails don’t eat each other. Usually, they will ignore each other. However, there are a few exceptions, like when they mate or if they congregate to share the picking.

Read: How Many Assassin Snails Should I Get? (Complete Guide!)

How Long Does It Take An Assassin Snail To Eat Another Snail?


As a general rule, assassin snails start their action within a few seconds as they are pretty fast and don’t tend to waste any time eating the pest snails. However, if your assassin snails aren’t eating the other snails, it can be because of the inadequate temperature.

Assassin snails are carnivores in nature, and they are fond of eating Ramshorn Snails, Malaysian Trumpet Snails, and pond snails that happen to move by. 

However, even after adding the assassin snails for a considerable amount of time, they don’t seem interested in eating the pest snails? Then, there are a few things to keep in mind.

#1. Temperature

If the temperature is quite low, then that may be the root cause of this problem. Your snails may be too cold that they have no other options other than hiding under the substrate.

You can check the tank temperature, adjust it to something comfortable, and see what happens. This act can, in turn, promote their breeding behavior and further increase their appetite.

The recommended tank temperature is 68° – 75° F (20° – 24° C)

#2. Feeding

Though, in general, it is not recommended to starve the assassin snails; still, you can try to limit the feeding you give to these snails up to some extent and see if that helps. Once your assassin snails start working for food, they will most likely look toward the pest snails in your tank.

#3. Size

The assassin snails are known to eat pest snails. However, if the cavity of the other snail is too small, then the assassin snail may not be successful in entering into that. Maybe their proboscis is too large for doing that task. 

As a rule of thumb, the assassin snails will ignore anything that happens to be less than 1/10th of their size (as they can’t enter in their cavity).

#4. Eating Speed

Based on the size of their prey, Assassin snails are needed to consume one to three snails per one to three days. 

So don’t expect magic just after adding them to your tank. You need to be patient here and let them do their task. 

And if you are really in a hurry and expecting more from them, you might have to add another assassin snail to get the work done.

Will Assassin Snails Kill Fish?

As a general rule, assassin snails don’t attack any fish actively. However, they eat almost anything they can scavenge, including decomposing fish and other small invertebrates.

Although assassin snails are opportunistic feeders, fish and plants are generally safe from them. On the contrary, your assassin snails might be in danger because of other fish tank mates. 

Loaches, pufferfish, cichlids, and certain catfish will consider them as their potential food. And if you are concerned about the safety of your assassin snails, then remember that most common community fish will likely not cause any problem.

Read: Do Yoyo Loaches Eat Snails?

Do Assassin Snails Eat Shrimp?

Assassin snails do eat shrimp; however, it is really a rare phenomenon. As a general rule, assassin snails will eat shrimps if they don’t have enough food to eat, if the shrimp is ill or genetically weak, but it is highly unlikely for a snail to catch a healthy and strong shrimp.

If you have healthy shrimps, then generally, you don’t need to worry much. Shrimps are fast and cautious whenever they sense any threat near them. 

They won’t lose much time making a sudden jump to protect themselves. But on the other hand, assassin snails are relatively very slow to catch or attack active shrimp.

However, if the assassin snail catches any shrimp, it is most likely either an ill, slow, or genetically weak shrimp. And if you consider the ecological viewpoint, this phenomenon actually allows you to have a stronger and better shrimp colony later on.

Another reason the assassin snails could eat the shrimps is that the assassin snails might not have access to an adequate amount of their preferred food source.

If their preferred food source is not present in enough quantity, then probably they would move towards the next best food source available to them. 

So, in short, the shrimp and assassin snail combination can be ok, but it does have some risks. Although rare, the possibility of an assassin snail eating a shrimp always remains. Hence, it’s up to you!

Now let’s look at the most interesting part – how the assassin snail kills.

Here’s How Assassin Snails Kill:

Assassin snails either actively hunt for their prey or patiently wait. When they get near the prey snail, they hold it with their foot and use their proboscis to suck the snail, eating it while it’s still alive.

When the assassin snails hunt for the live snails, they will typically bury themselves into the substrate whenever possible. 

They wait in that position with their extended proboscis (feeding tube) sticking out. And as soon as their victim is close enough such that they can assassinate, they just emerge and start feeding.

On the other hand, if there is no sand substrate to bury themselves, the assassin snails will actively search for food around the aquarium for other snails they can eat.

The interesting thing to consider is that if the assassin snails get attracted to attack a larger snail, then they can gang up together and take it down in force. 


So that was all about how and what assassin snails kill and eat. If you want to get rid of pest snails in your aquarium, but don’t want to get a snail-eating fish, then these assassin snails can be a good option. 

You need to be aware of their carnivorous nature and house them only with tank species they are comfortable with. That’s it! I hope you found this guide helpful!

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