How Big Do Assassin Snails Get? General Information For Aquarists

The Assassin Snail (Clea Helena) is a freshwater snail of the Nassariidae family. They are native to Thailand, Malaysia, and Indonesia but can be found in ponds or ditches throughout Southeast Asia.

These snails are characterized by brown and yellow striped shells. They are highly sought after in the aquarium market due to their hardiness, low-maintenance nature, and ability to prey on other pest snails that might be taking over the tank.

While keeping a small group of Assassin Snails in a tank may keep freshwater snail populations in check, some aquarium lovers may wonder: “How big do Assassin Snails get?” so they can prepare a suitable tank for them. If you share the same concern, look for the answers and helpful information below.

Why Do People Keep Assassin Snails In Their Aquarium?

Many aquarium owners want to keep Assassin Snails since they have an eye-catching appearance that can be a colorful addition to the tank.

Assassin Snail

Besides, they are also known for their predatory nature, which helps eliminate unwanted pest snail populations in the tank. Simply drop a few Assassin Snails in your aquarium, and the issue is solved. Also, as they are not interested in aquatic plants, the plants are not at risk of getting devoured.

Another reason why aquarists keep Assassin Snails is that this species is peaceful and can thrive in various water conditions, making it appropriate for community tanks or planted aquariums.

How Big Do Assassin Snails Get?

The Assassin Snail is a small invertebrate of about 0.8 and 1.25 inches in length. However, when raised under appropriate conditions, some can reach 3 inches. So make sure to provide a tank with a suitable size and capacity to facilitate their growth. Besides, wild species are often larger than those grown in captivity.

Tank & Water Requirements For Assassin Snails

Tank requirements

Taking care of Assassin Snails is relatively easy since they’re peaceful and can adapt to various tank conditions. However, the minimum requirement for their tanks is at least 10 gallons in size, increasing by 3 gallons per snail. But a larger capacity is better for them to react to changes.

Besides, the growth rate of Assassin Snails should also be taken into consideration. As they age, they grow in size, requiring more snails to consume. Also, they are often housed in a group of five or more, so the population of snails can exceed the tank. Therefore, nano tanks are not ideal for the growth and living of Assassin Snails.

Water requirements

They thrive in aquariums that simulate their natural habitat. In particular, they prefer hard water on the alkaline side and healthy, stable parameters with a soft-grained substrate at the bottom of the tank. Ideally, the substrate needs to be loose and thick enough for the snail to scrape.

Assassin Snails are sensitive to water fluctuations so any significant temperature shift can lead to shell problems or even death. Hence, only drop them into the tank when water parameters are stable, and the temperatures are on the warmer side.

  • Water temperature: 70 to 80 degrees Fahrenheit
  • pH levels: 7.0 to 8.0
  • Water hardness: 2 – 15 dKH

It’s best to use a thermometer to check the water temperature. Do not apply filters that provoke a strong current since Assasin Snails get used to slow-moving water.

Assassin Snails Care Guide

Food & diet

Assassin snails are carnivorous, so they only consume protein-based foods. They enjoy feeding on unwanted pest snails in the tank, commonly Trumpet Snails, Rabbit Snails, Ivory Snails, and Ramshorn Snails. Typically, they can eat 1-2 snails a day.

In addition to eating snails, brine shrimp, water fleas, and bloodworms are their favorite foods. Assassin Snails may also be fond of eating other snail eggs, but not their own eggs.

Besides, you can supplement the Assassin Snails with protein-rich sinking wafers. The ideal time to feed them is at night when they’re most active.

General care and requirements

  • Provide the Assassin Snails with a rich diet of protein and calcium.
  • Offer this species 8–12 hours of light per day.
  • Avoid water Instead, keep the water warm and stable.
  • Tanks should be covered with a secure lid to reduce the risk of Assassin Snails escaping.
  • Cover power filter intakes with a sponge pre-filter to prevent the snail from getting their bodies trapped and getting hurt or killed.
  • Since Assassin Snails are active, it’s suggested to have some rocks and climbable driftwood for them to explore.
  • Although this species does not necessarily require plants, you can add vegetation to the aquarium to circulate a strong current. A recommendation is hardy plants such as Anubias or Bolbitis.

Diseases & treatment

Common health issues that Assassin snails may have to face include:

  • Parasitic infection: Usually, they appear as white spots on the shell. To treat the infection, it’s better to break the parasite’s life cycle. But avoid adding copper-based medications to the tank because they’re lethal and kill off snails quickly.
  • Brittle shell: A lack of calcium or poor water quality is the culprit of brittle shells in Assassin Snails, causing the shell to break apart. Treat brittle shells by providing the snails with appropriate calcium and keeping the water clean.
  • Stunted growth: Stunted growth can happen when Assassin Snails lack nutrition or do not have enough space to grow in the tank. To solve the problem, place them in a suitable tank and ensure they are well-fed with enough protein-rich food.

Assassin Snails Tank Mates

Since Assassin Snails are carnivores, tank mates should be carefully considered. But luckily, they are not likely to attack species larger than them. They are comfortable with community tanks with docile fish. They also do well with small freshwater clams and with shrimp.

Some favorite tank mates for Assassin Snails include:

  • Cory Catfish
  • Guppies
  • Otocinclus Catfish
  • Cherry barbs
  • Tetras
  • Freshwater clams
  • Certain species of shrimp (Bamboo Shrimp, Viper Shrimp, or Ghost Shrimp)

Hence, never pair them with aggressive types like Cichlids or other fishes that may eat them.

Wrapping Up

Now that you’ve grasped several helpful pieces of information about Assassin Snails. As they are fantastic freshwater species with impressive ability to get rid of any pest snails in your tank, we highly recommend adding some to your tank. So what’re you waiting for?