Assasian Snail (CLEA HELENA) – Large


An Assassin Snail is a good snail to keep in a planted tank. Assassin Snails are not interested in eating plants at all, so there is no risk the plants will get devoured. And pest snails may enter a tank by hitching a ride on aquarium plants, so Assassin Snails may really help keep their population in check.

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approximately 1-6 business days September 29, 2021 - October 4, 2021


Assassin Snails (Clea helena) are one of the most useful animals in the aquarium hobby.  They will obliterate unwanted pest snails and eliminate the need to use harsh, snail-killing chemicals in your aquarium.  They are particularly adept at handling populations of pond snails, Malaysian trumpet snails, ramshorn snails, bladder snails, and more!

To demonstrate an example of the Assassin Snail’s prowess, we have kept several 30 gallon tanks that were completely overrun with hundreds of unwanted pest snails, and a crew of 5 “assassins” demolished them within a couple of weeks.  They eat all other types of snails that are their size or smaller, but they will not harm snails that are larger (such as Mystery Snails, Giant Sulawesi Snails, and larger Nerite Snails).  However, large groups of Assassin Snails have been known to gang up on a larger snail and take it down, so caution should be exercised when keeping these, even with larger snails.  They are safe to keep with fish, most invertebrates, live plants, and other aquarium inhabitants because their preferred meal are snails. But some caution needs to be taken when housing them with dwarf shrimp. There is a slight risk of an assassin snail eating a dwarf shrimp from time to time. They would much prefer to eat snails, but if given the opportunity there is a chance they could get a shrimp. So caution must be used when housing with other snails and dwarf shrimp.

As an added bonus, Assassin Snails are rather attractive in appearance.  Due to their yellow and black/dark brown striping, they look fantastic on both light and dark-colored substrates.  Their shells are spiral-shaped and taper down to a point at the end.  Their bodies are an iridescent, almost translucent white color and consist of a long Proboscis (a sucking mouthpart, similar to a nose) that they use to drag themselves around, as well as two eyes underneath two tentacles.

We ship younger Assassin Snails that are about 1/4 to 1 inch in length, and they will grow to about 1 inch long as adults.  Having good substrate is important with Assassin Snails, as they love to burrow in it; we recommend sand.  As with all snails, these are very sensitive to copper, so we advise monitoring copper levels if tap water is used to fill the tank.


What We Like About These Snails:
  • Obliterate pest snails
  • Attractive striped coloration
  • Safe with plants
  • Does not bother most tankmates other than snails
  • Temperature:  68° – 75° F (20° – 24° C)
  • pH:  6.5 – 8.0
  • KH:  2 – 15 dKH
  • Minimum tank size:  2 gallons per snail
  • Diet:  Carnivorous.  Voraciously eats other snails and will often eat dead fish.  If there are not enough small snails in the aquarium, their diet can be supplemented with fish flakes, blood worms, and other meaty foods.
  • Social behavior:  Attacks other snails, but otherwise peaceful.
  • Origin:  Indonesia
  • Average adult size:  1 inch (2.5 cm)
  • Average purchase size:  .25 – 1 inch (.6 – 2.5 cm)

An Assassin Snail has become a popular freshwater snail to keep. Assassin Snails have a reputation of being able to help keep populations of some other freshwater snails in check. While keeping a small group of Assassin Snails in a tank may reduce the numbers of Trumpet Snails somewhat, Assassin Snails should not be considered the only solution to snail population explosions. Keeping Trumpet Snail populations in check can also be achieved by removing excess uneaten food from substrate by regular vacuuming.

Questions about Assassin Snail issues commonly involve:

What To Look For When Buying Assassin Snails In Stores

Where Can I See Pictures Of Assassin Snails In Action?

What Are Some Care Issues For Assassin Snails In Freshwater Tanks?

How Big Do Assassin Snails Get?

What Is A Good Tank Size For Assassin Snails In Groups?

How Long Do Assassin Snails Live?

What Do Assassin Snails Feed On?

Do Assassin Snails Eat Live Plants?

Do Assassin Snails Breed And Reproduce In Aquariums?

What Are Good Tank Mates For Assassin Snails In Aquariums?

When Buying An Assassin Snail From Stores

When buying Assassin Snails look for specimens that appear active. An Assassin Snail should be affixed to hard surfaces like aquarium glass or decorations. An Assassin Snail has a cone shaped shell, similar to the shells of Malaysian Trumpet Snails and Rabbit Snails. Assassin Snail shells are gold color with a dark brown stripe wrapping around it from aperture to apex. Their shells should appear free from cracks, splits or other damage and their operculum should be visible on the top of their foot near their backside.

An Assassin Snail body and foot are a light cream color, with darker specks sprinkled throughout. Make sure the Assassin Snail has a complete Proboscis, as well as two tentacles, with an eye near the base on each. Be mindful that snails may be kept in display tanks with rougher fish that may take nips at them. So make sure the snail looks healthy, active and complete.

Avoid buying Assassin Snails from display tanks with an unusual amount of dead or sick looking tank mates, as these can be indications of poor conditions and unhealthy snails. Also avoid buying Assassin Snails if the they appear motionless on the tank bottom or floating as these can be indications the snail is sick or dead. Finally, check to make sure the snail shell isn’t empty.

Assassin Snails, Upclose: 20 Second Video

Additional information

Weight1 g