Snails are quite popular for home aquariums nowadays. However, certain snail species can become pests if introduced without your say-so, for example as hitchhikers on plants. When trying to remove these, your first thought should be to use assassin snails. It might not make the most sense to add snails when you want to clear them out, but assassins are carnivores and will snack on your pests until they’re eradicated. You’ll get an attractive, stripy species that won’t eat any of your plants, so they’re not just for people with a pest problem. If you’re looking for some new tank mates to mix it up from just keeping fish, assassins are a great option.
Maximum size: 2cm
Ideal number kept together: 1+
Hardness: 300-800 ppm
Temperature: 18–28 °C
Ease of care
If you’re looking after snails for the first time then you need to realise that assassin snails can get diseases just like fish can. Their shells can be affected by a number of issues. It’s not always easy to keep their shells strong and healthy. If they weaken then they could crack and break; this would most likely be fatal. Calcium is important for maintaining a hard shell. They should get this from their diet, but you can add calcium supplements into the water if they’re not getting enough. The shell’s growth can be stunted if temperatures are too low or if they aren’t eating enough. One element to keep away from your tank is copper. This is toxic for most invertebrates. Check the contents of anything you add to the water, medications often contain some degree of copper. Assassins are particularly susceptible to poor water quality; they need consistently clean water to stay healthy. Perform regular water changes (every 1-2 weeks) to keep the nitrate levels to as low as possible.
Assassin snails are a carnivorous species, so their diet doesn’t include any vegetation. They’ll ignore any plants in the tank; you don’t need to worry about these snails damaging them. They’ll ignore algae too, unlike most other freshwater snails. If you want a gastropod to clean up your algae problem, look elsewhere. They will eat are other snails, so fishkeepers sometimes use assassins for pest control. Trumpet and Ramshorn snails are a couple of the most popular snacks. Soft snail eggs and shrimp fry might be of interest too. We recommend supplementing their diet with a high quality pellet or wafer.
Your snails will pay little attention to any fish you add, so in that sense you can add anything you like. The problem is that there are lots of fish that might try to eat your snails. You should be fine will most common community fish. Small species that swim in the mid-levels of the tank will be fine: cherry barbs, celestial danios, guppies and neon tetras are some good examples. Some bigger options are peaceful gourami (like dwarfs or pearls), rainbowfish or angelfish.
Breeding / Sex
Assassin snails are happy to breed in captivity, so you have a good chance of growing your own population if you want to. They’re not hermaphrodites like lots of other gastropods. They have defined sexes but it’s virtually impossible to tell male from female. Your best chance is to make sure you have a good sized group (6 or more) so that the odds of having individuals of both sexes are well in your favour.