Can Aquarium Snails Kill Fish? (Freshwater, Mystery, Assassin Snails)

Image of a snail in an aquarium

Many aquarium owners like to liven up their tanks by keeping small creatures like shrimp and snails with their fish. However, keeping different types of animals in the same space can present unexpected and unique challenges. Unless the animals are compatible, the peace of the tank will be affected. Hence, you should evaluate whether your snails and fish will get along or stress each other. So, can aquarium snails kill fish?

Aquarium snails will not harm healthy fish. However, they will rush to dead fish and devour it. Snails will also not hesitate to approach and eat rotting skin or flesh of weak and sick fish that do not move around. So to keep snails with fish, you will need to ensure that the fish are healthy.

Let’s talk about this a bit more.

What Should You Know About Keeping Snails In Your Fish Tank?

Some fish tank owners deliberately introduce snails into their aquariums. These tiny creatures add beautiful colors to the tank and become beautiful natural aquarium ornaments. But more importantly, they also do a fantastic job of cleaning the tank.

Snails are scavengers. They feed on all the dead and decaying matter, algae, and debris in a tank and keep it clean.

Now, snails can find their way into a fish tank in the most unexpected ways. Even if you do not put them there, don’t be surprised if you find a snail or perhaps many snails in your fish tank one day.

Most of the time, snails hitch-hike on live plants and find their way into the tank. Snail eggs are microscopic structures that stick to the leaf surface of aquatic plants. So, if you directly introduce a live plant into your tank, it may contain snail eggs that will later hatch into live snails. Another possibility is when you add fresh gravel or sand to your tank. Snail eggs can enter the tank in this way too.

The problem with snails is that they breed profusely. Unless you employ proper control measures, the snail population in your tank can explode and become a menace before you know it. Even ornamental snails can become a headache if you allow them to breed.

Nevertheless, snails can also have a positive effect on an aquarium. Let us take a closer look at how they affect a tank.

Advantages Of Keeping Snails

  • Snails will eliminate the debris and decaying matter in the tank.
  • They will clear out algae, dead leaves, and dead fish.
  • Snails will also eat any leftover food before it rots and pollutes the water.
  • Their continuous cleaning will improve the water quality and reduce the need for frequent water changes.
  • By burrowing into the substrate, some snails improve the aeration of the soil.

Disadvantages Of Keeping Snails

  • Snail populations can quickly get out of control. It can lead to an ecological imbalance and strain the existing resources in the tank.
  • Snails can hide in hard-to-reach places. They tend to get stuck in filters and valves, causing blockages that are hard to fix.
  • They can carry diseases that affect fish. Snails can also harm weak and sick fish.

Recommended Further Reading:

Snails And Fish – Likely Problems That May Arise

Most tank owners are primarily concerned about their fish than the other creatures in the tank. Invertebrates like shrimp or snails and aquatic plants only play a supporting role in the space. So, you may be more concerned about keeping the fish comfortable and healthy. In this regard, it makes sense to explore how the presence of snails can affect the fish in your tank.

On the one hand, snails clean the tank and make it a better living space for the fish. Clean water will help your fish thrive. When snails do a good job of cleaning the water, you will not need frequent water changes.

However, too many snails can alter the balance of the tank. They can become an additional burden on the limited resources. They consume vital oxygen, defecate frequently, and add to the bio-load.

When the number of snails in a tank increases drastically, they pollute the water faster than they clean it. Dirty water can be detrimental to the overall well-being of your fish.

Another factor to consider is that aquarium snails like to feed on aquatic plants. This can reduce the availability of plants for fish that like to graze on them.

Additionally, snails can carry parasites and germs that cause infections in fish. It increases the chances of your fish becoming ill. For instance, snails may carry nematodes that cause black spot disease in fish. Although snails brought from home aquariums are less likely to carry such infectious agents, you cannot entirely dismiss the possibility.

Now, snails will not attack healthy fish. They are too slow to catch up with moving fish. Additionally, their mouths are soft to feed on the meat of healthy, live fish. However, snails will devour dead fish.

They will also pounce on sick and slow-moving fish. If there’s any exposed rotting, damaged, or decaying flesh, the snails will target these areas. It will harm the fish, cause suffering, and reduce its chances of recovery.

Related Further Reading:

Will Freshwater Snails Harm Aquarium Fish?

Certain fish will attack aquarium snails, and not the other way around. Loaches and cichlids are common aquarium fish that snack on snails. Snails do not generally attack or chase their food. Most varieties are peaceful creatures that mind their own business.

Nonetheless, snails can be a threat to fish that are already weak or dying. If a fish does not move or it has exposed rotting flesh, snails will not wait till it is dead to approach it.

Most aquarium snails will also eat any fish eggs that they find in the tank. So, if you want to breed fish, it is a good idea to separate the pregnant fish from a tank that has snails. Fish eggs already face the risk of being eaten by fish. But, with snails around, their chances of survival are further reduced.

Use a breeding tank for your fish to improve the chances of the eggs surviving and hatching into fry.

Can Mystery Snails Kill Fish?

Many fish hobbyists like mystery snails because they do not harm plants and look very beautiful. It is also easier to keep the population of mystery snails under check.

Mystery snails generally prefer to eat dead plants and vegetation. They do not chase after fish or attack them. Nonetheless, mystery snails are opportunistic feeders. They target dead fish and devour them within hours. Mystery snails will also approach dying or weak fish and euthanize them if they get the chance.

Interesting Further Reading:

Can Assassin Snails Kill Fish?

When the snail population gets out of control, assassin snails can bring the situation under control. These carnivorous snails eat other small creatures, including snails. Since they are very slow, they will usually not bother the fish. But assassin snails will target any animal that is small enough to be prey.

Although assassin snails do not usually attack fish, they are drawn to sick fish if they are starving. Even so, the fish must be extremely weak and unable to move for the assassin snail to get to it. They will also eat shrimp and other small and sick invertebrates. These meat-eating snails will also graze on fish eggs in the tank.