Assassin Snail
Behaviour Active on surface both during day and night, sometimes dormant. Grows to around 2 cm
Max size 2cm
Tank Area Bottom cm ℃ ℃
Feeding Other snails! will also scavenge and eat sinking foods or wafers
pH Range 6-8.5
Hardness vs,s,m,h,vh
Assassin Snail Antentome helena
  • Assassin Snail Antentome helena - thumbnail
  • Assassin Snail Antentome helena - thumbnail

Assassin Snail

Antentome helena

The Assassin Snail is an ironic solution to the problem of snails over-running an aquarium, since it has the ability to hunt down and kill other snails. Assassin snails will hunt for any similar sized or smaller snail of another species and literally suck it out of its shell. They are of particular use in controlling the tricky Malayan Trumpet Snail, which can rapidly reproduce and overrun an aquarium. Even the other snails seem to know they are in trouble when assassins are added to the tank, since they can often be seen changing habits and heading up to the surface. Assassin snails are reportedly not a fast reproducer, so one snail problem will not be swapped for another, and if they do reproduce at least they have value and can be sold on or given away. Once the assassins have cleared up any other snails, which may take some time depending on numbers, they will happily feed on debris and algae wafers although they are not a great algae eater. The assassin snail does not tend to eat its own kind and has a quite attractive shell, so a few can be an ideal addition to a tank in their own right, or as a method to control other snail populations. No special requirements are needed to keep these snails and they will settle into most tanks without predators.

Since the snails are 'recyclers' and do not increase the overall waste load on an aquarium, they have a stock level of zero in the Compatibility Checker 

| Other names Beast Snail, killer Snail | Origin Indonesia | Breeding Lays eggs

Have a Assassin Snail Problem or General Question?

If you have a question about keeping Assassin Snail's then please use our Assassin Snail help forum. Join 100's of other fish enthusiasts with 1000's of years experience between them.

question mark     

Think Fish Community Creator - Assassin Snail

Please check your water type for compatibility with your fish, which can be found on the Assassin Snail information box.

If you'd like to talk about the "Assassin Snail" with our users, then we have a buzzing community of fish enthusiasts where you can talk about tank issues, fish behaviour, tank stocking and any other issues related to the Assassin Snail fish or other types you may have!

To save your details in the Fish Community Creator you must be logged in CLICK HERE to log-in or join

Like this tool? Help keep us online by becoming a think fish supporter and helping with our hosting and development costs!

Tank Details
question mark  Rename your tank:
question mark  Length: (cm)
question mark  Volume: (Litres)
question mark  Filter type:

* This fishtank will only last for this session - to save your tank please Join/Log in

question mark  Max Stocking level: 0cm
0-1 months 20%: 0cm
1-3 months 40%: 0cm
3-6 months 60%: 0cm
question mark  Current stock level: 0cm
Stock percentage: 0%
question mark  Suggested maximum
fish size for your tank:
My Fishtank Quantity Stock cm
There are no fish in your fishtank. To add fish, view a fish profile and click the 'Add to My Fishtank' button
This tool is a guide only. All fish have individual natures and compatibility can never be guaranteed. If you spot anything you think needs improving, contact us at

Click to read the Latest Think Fish Discussions from Thinkfish users.

Tropical Fish Keeping Help and Advice
Fish of the month