Snails can be a delightful addition to any aquarium, but their populations can sometimes explode, leading to a nuisance. While some aquarists turn to snail-eating fish, these often grow too large or exhibit aggressive behavior. Fortunately, the assassin snail ( Anentome helena or Clea helena) offers a natural and effective solution to snail population control. These useful snails have found their way into the mainstream aquarium hobby. If you don't want to leave the comfort of your home just to go out and buy a few snails, you can easily order these assassins online at The Shrimp Farm.
Natural Habitat and Adaptation
The wild assassin snails are naturally found in rivers, ponds, and lakes throughout much of Southeast Asia, including Thailand, Malaysia, and the island of Sumatra in Indonesia. Unlike most of its cousins that inhabit marine and brackish environments, the assassin snail thrives in freshwater habitats. In the wild, they're among the only members of their genus that can thrive in stagnant waters like ditches rather than exclusively inhabiting fast-flowing streams.
Appearance and Size
Anentome helena, also known as Clea helena, is a beautiful freshwater snail with a pointy, spiral shell that reaches up to 1 inch (2.5 cm) long. Assassin snails ( Clea helena) can grow to about 1 to 1.25 inches in length when fully mature. The shell has a ribbed texture and is easily recognized by the alternating dark brown and yellow stripes that look like a bumblebee pattern. The shell is generally light brown to yellowish-brown, with dark spiral bands running across the shell. The soft body of the assassin snail is typically translucent white or light yellow, which contrasts with the darker shell. They have two pairs of tentacles. Aquarists have asserted that their assassin snails prefer eating trumpet snails, but generally speaking, they'll go for any species they can catch.
Aquarium Setup and Care
If you're interested in acquiring a few assassin snails, tank size is not much of an issue. Nano fish tanks of 5 gallons or up should be absolutely fine for one or two of these snails. Because of its small size, one snail can easily live in 2 gallons of water or more at temperatures of 70-80°F (21-27°C). Assassin snail care is pretty straightforward. Your assassin snail aquarium should be filtered, fully cycled, and heated.
Water Parameters
Like most snails, it prefers alkaline pH from 7.2-8.0 and moderate to hard GH. Although assassin snails can adjust and thrive is a wide variety of water parameters, there is always an ideal range which you should try to match at all times and provide a stable environment. The most important factor to keep in mind for any snail (besides the nitrogen cycle) is water hardness. Stability with a gentle lean alkaline is the theme. Temperatures in the mid-70s to low-80s °F keep activity up and incubation times reasonable. A pH in the low eights with measurable carbonate hardness protects shells from dissolution and buffers against sudden, acidic dips that etch growth rings into chalk. General hardness supplies calcium and magnesium-the literal minerals of shell.
Read also: Comprehensive Overview: Assassin Bug Diet
Substrate and Decor
Fine Gravel or Sand: These snails like to burrow and move around the substrate in search of food, especially pest snails. Fine gravel or sand is ideal for this, as it won’t damage their bodies and allows easy movement. Sand is not décor; it is survival. Juveniles need fine substrate to disappear into, and adults use it for camouflage and ambush. Provide a sand or smooth-gravel zone and give them textured hardscape for egg deposition and biofilm.
Tank Size and Setup
Minimum 10 Gallons: While assassin snails are small, they still need enough space to roam. A 10-gallon tank is suitable for a small group. Snails need to be well kept and cared for so you need a well-maintained tank. Use a gentle filtration system to ensure there are no sharp currents that could stress them. Assassin snail aquarium should be filtered. Rocks and Driftwood: Assassin snails enjoy hiding in crevices and exploring different areas of the tank.
Plants and Lighting
Live Plants: While assassin snails don’t rely heavily on plants, having some live plants (like Anubias, Java fern, Mosses, etc) can improve the aesthetics of the tank and give snails a more natural environment. You can absolutely keep live plants with Assassin Snails. These snails will not eat or damage your plants, and they will help with controlling pest snail populations. Moderate Lighting: While assassin snails are not particularly light-sensitive, moderate lighting will help plants in the tank to thrive.
Diet and Feeding
You probably won't be surprised to find out these snails are mainly carnivores. As mentioned before, these carnivores love to eat snails of all kinds, and given the opportunity, they will also eat deceased animals, fish eggs, and newborn fry (or wrigglers) that are not freely swimming yet. In the aquarium, their carnivorous nature is one of the main reasons people keep this invertebrate. Aquarists have asserted that their assassin snails prefer eating trumpet snails, but generally speaking, they'll go for any species they can catch.
This being said, assassin snails will also eat algae, plus any leftover fish foods and shrimp pellets they can find. Feeding assassin snails is easy: you can supplement their diet using commercial fish foods, like fish flakes, as well as frozen foods like blood worms or brine shrimp. When you run out of pest snails, you can feed them any kind of high-protein fish food, such as frozen bloodworms, fish flakes, pellets, sinking wafers, and Repashy gel food.
Read also: Feeding Giant African Land Snails
Tank Mates
If you want to keep assassin snails, you must choose their tankmates wisely. Given its common name, you should remove all snails that you do not wish to get eaten. When kept in groups, assassin snails have the ability to take down larger snails, such as mystery, nerite, and Sulawesi rabbit snails. Smaller snails (and not just pest snails!) are bound to get eaten sooner or later.
You can keep assassin snails with various fish species. Assassin snails usually ignore plants and coexist with most fish that won’t eat them. Despite the scary name, Assassin snails can have tank mates. Assassin snails are peaceful toward most non-snail tankmates. Loaches - such as Clown loaches, Yoyo loaches, Zebra loaches, Skunk loaches, to name a few.
Shrimp
There is some debate about whether assassin snails are shrimp safe or not. They are broadly compatible with Neocaridina Shrimp and Caridina Shrimp, provided you feed well and keep molts protected in plant thickets and wood. It is always very important to monitor behavior when keeping Assassin snails with shrimp, especially neocaridina or caridinas. Adult Shrimp: Larger or adult shrimp (such as big neocaridina shrimp, bamboo shrimp, vampire shrimp, Ghost Shrimp) are typically safe from Assassin Snails. These snails mainly target snails, particularly small or weaker ones, and will not usually hunt shrimp unless hungry. Sufficient Food: If there is plenty of food for both the shrimp and snails, they are less likely to interfere with each other. Assassin Snails usually hunt for other snails, not shrimp, but they will need an adequate food supply. Plenty of Hiding Spaces: Providing plenty of hiding spots in the tank is crucial for shrimp, as they often feel safer in places where they can retreat. Well-Planted Tanks: A well-planted tank with enough live plants will allow both shrimp and snails to have their own spaces. You can keep shrimp and Assassin Snails together as long as the shrimp much bigger than the assassin snails and the tank is well-maintained with plenty of hiding places and food for both species. Keep an eye on baby shrimp, as they are more vulnerable, and ensure there is enough food to prevent competition.
Breeding
Breeding assassin snails is just easy enough to be an enjoyable project for beginners, but just difficult enough to avoid ending up with another snail infestation. Assassin Snails (Clea Helena) are fascinating creatures when it comes to breeding and reproduction. Unlike many pest snail species, assassin snails are not hermaphrodites and cannot reproduce by themselves. Assassin Snails have distinct sexes, meaning there are males and females. However, it's not easy to tell them apart just by looking at them. They are sexually monomorphic, meaning both sexes look the same externally.
All you have to do in order to get your assassin snails breeding is get a group that's large enough to guarantee the presence of both males and females. They are difficult to sex, so the easiest way is to get a group of six or more to increase your chances of having at least one male and one female for breeding purposes. Begin with a cohort rather than a pair to let probability supply both sexes. Feed high-quality, nutrient-rich foods and make sure the water quality is always high. If you feed them plenty of food, they will naturally begin to reproduce, although at a much slower rate compared to most pest snails.
Read also: Learn About Apple Snails
Courtship and Egg Laying
Courtship: Mating often involves a bit of "courtship" behavior, where snails engage in slow movements, touching each other with their tentacles and potentially rubbing their shells together. Sperm Transfer: Snails have a specialized reproductive system, and the male will transfer sperm to the female during mating. Females deposit single eggs in square to rectangular capsules on wood, rock, glass, or plant bases, one at a time, often in short rows. Assassin snail eggs are laid one at a time, totaling up to four per clutch. Appearance of Eggs: Assassin snail (Clea helena) eggs are small, square to rectangular capsules, translucent to yellowish in color, around 1-2 mm in size, and always firmly attached to something. Usually laid one at a time, not in clusters. Inside each capsule, you'll see a single developing embryo. The female will lay a translucent, square-shaped egg capsule with pointy corners that contains a single yellow egg inside. These egg capsules are laid one by one and will stick to various surfaces like rocks, driftwood, or even the substrate.
Hatching and Growth
Egg Development: Eggs typically take around 3-4 weeks to hatch, depending on the temperature of the water. Hatching ≈52 ± 6 days at 25 °C; direct development; hatchling size. Development is direct-there is no free-swimming larval phase-and temperature is the metronome’s hand. In a controlled culture at 25 °C, hatching occurred in about 52 ± 6 days and hatchlings measured roughly 3 mm, already shaped like miniature adults.[1] Warmer conditions within the safe range shorten the schedule; cooler conditions stretch it.
Baby Snails: Once the eggs hatch, you will see tiny baby snails that are fully formed and can move around right away. Baby assassin snails hatch after around two months, tiny but fully functional. Feeding: Baby snails will eat detritus, algae, and leftover food. Ensure there's enough food for them to grow and thrive. Growth: The baby snails will gradually grow and start hunting small prey (like pest snails) once they are big enough. Space and Tank Conditions: Having enough space and the right tank conditions can help prevent overcrowding. Resist the urge to polish every surface; the nursery lives under the sand. After hatching, juveniles vanish into the substratum and live a cryptic, sand-dwelling childhood. This is normal, not a failure of husbandry.
Selling
Eventually, if you get a good number of assassin snails, you can sell them to your local fish store or aquarium club. While we do not ship live animals, we have a list of preferred online vendors that sell high-quality fish, shrimp, and snails and offer fast shipping right to your front door.
Health Issues and Prevention
Assassin snails ( Clea helena) are generally hardy, but like all aquatic creatures, they can still suffer from certain health issues and diseases. Although snails are less prone to diseases compared to fish, they can be affected by environmental factors, poor water quality, and pathogens.
Poor Water Quality
Poor water quality is the leading cause of health problems in assassin snails. Often linked to poor water quality, high levels of ammonia or nitrites, or physical trauma to the shell. Ensure high water quality, maintain stable conditions, and avoid sharp objects in the tank that could damage the shell.
Parasites
Though uncommon, snails can carry or become infected with external parasites, such as trematodes(flatworms) or gill flukes. Typically, snails become infected when introduced to new tankmates or if water quality is poor. If possible, quarantine new snails before introducing them to the main tank. Treatment can involve using anti-parasitic medications designed for snails.
Copper Poisoning
Copper poisoning usually occurs when medications containing copper are used without proper precautions or if the water has elevated copper levels from treated plumbing. Avoid using copper-based medications in a tank with snails, or if you must treat with copper, remove the snails first.
Physical Trauma
Avoid rough handling or introducing sharp objects into the tank.
Overfeeding
Overfeeding can lead to excess food in the tank, which can rot and degrade water quality, impacting the snails' health. Feed snails sparingly, and remove any uneaten food after a couple of hours.
Chemicals and Medications to Avoid
There are several chemicals and medications that can be toxic to aquatic snails, including assassin snails ( Clea helena), and other invertebrates in your aquarium.
- Copper-Based Medications
- Formaldehyde is sometimes used in medications for treating external parasites like skin flukesor fungal infections.
- Metronidazole
- Antibiotics: While antibiotics are important for treating bacterial infections in fish, they can often harm snails and other invertebrates.
- Organophosphates
- Carbaryl
- Praziquantel
Purchasing Tips
When purchasing Assassin Snails ( Clea helena) from a physical store, it's important to ensure you're getting healthy individuals that will thrive in your aquarium.
- Check for Activity
- Inspect the Shell
- Size: Juveniles are small and may be more fragile.
- Online Purchases: When purchasing online, make sure to always select a reputable seller to buy from and inspect the snails upon arrival. Keep in mind that most assassin snails will arrive tucked in the shell and closed up.
Common Questions
Do assassin snails eat algae?
Not really, as they're mostly carnivores. Try some red racer nerites for algae control!
Will assassin snails eat mystery snails?
It's unlikely for an assassin snail to attack and kill a larger mystery snail, but we're not going to say it's impossible either. Consider the risk before combining the two.
Will assassin snails eat nerite snails?
Since nerites aren't very large, this is definitely a possibility. These two species are not a good combo!