N yotarou, CC BY-SA 3.0, via Wikimedia Commons

The Bladder Snail, which is also known as the Physella acuta is a species of small snails. This snail also has many common names and trade names, including, European Physa, Tadpole Snail, and Acute Bladder Snail. The Bladder Snail is known for being a left-handed (sinistral) air-breathing freshwater snail species. They are an interesting snail species to keep in the tank, some fishkeepers consider them pests and vote for their removal from the tank immediately. Meanwhile, many fish kippers oppose their views and vote for keeping them in the aquarium as they are a natural cleaner.

The fishkeepers that consider them a bad omen, often point towards the fact that these are an asexually multiplying species, meaning that they can increase in number rapidly as compared to the fish in the tank. That can tip the balance of the environment inside your aquarium, which is very bad. But the ones that advocate keeping them in the tank point out the fact that these natural creatures are found in the real-world environment where these aquarium fish live. So, having them around would help create a more positive environment. Both arguments are valid in the case of Bladder Snails, but the conditions are different for each one. Knowing more about this will help you decide if you should have them in your tank or you should remove them immediately. Read the article below to know more about Bladder Snails.

Basic Facts Table:

Lifespan2 Years
Size½ inch
ColorsGrayish with Yellow Spots
DietOmnivore, mainly Algae
Freshwater or SaltwaterFreshwater
Care LevelEasy
CompatibilityPeaceful fish species

Tank Companions:

When we are talking about Bladder Snails, we will have to look at the tank companions differently. Normally we talk about pairing a fish species with other fish that have the same temperament, or behavior i.e aggressiveness and peacefulness. But for the Bladder Snail, fishkeepers are encouraged to pair them with opposite behaving fish. The Bladder Snails are a very invasive species. Meaning that once they are introduced in an environment, they would multiply. As their number grows, they start pressuring the balance of the aquarium ecosystem, meaning that a time will come when they will make the aquarium non-livable for the fish species that you have kept in that aquarium.

But you can prevent this by introducing highly aggressive fish species in the tank with a Bladder Snail population. These aggressive fish species and large fish would attack the Bladder Snail population and would keep them in check. This would help to maintain the balance in your aquarium. So, if you are planning on introducing these into your aquarium, you should only introduce them in the tank with aggressive and large fish species that can control their population spread.

Here is the list of ideal fish and snail species that you should put in the Bladder Snail tanks to control their population.

  1. Loaches: Many species of loaches eat Bladder Snails. These are not only beautiful fish species that will make your aquarium look more attractive, but will also keep your aquarium clean and keep the population of the Bladder Snails in control. They not only eat the small Bladder Snails and their eggs but also large snails as well. So, if your aquarium has been infested with snails and they are mature-sized, then you should introduce Loaches, especially Yoyo Loaches. Yoyo loaches can grow up to 5 inches, meaning that they are big enough to eat these snails.
  2. Betta Fish: Betta fish is a carnivore fish species that feed on live invertebrates, and small larvae, eggs, and small Bladder Snails. If you are looking for a fish species that will not eat the large snails but keep the population in control by eating the eggs and newborn snails. Then you should put betta fish in your tank.
  3. Pufferfish: Pufferfish are also a small fish species that are very aggressive towards these Bladder Snails. Green Spotted Pufferfish is one of the most suitable fish species to introduce in your tank to control the population of Bladder Snails. It would not only eat the large snails, but also small ones and their eggs as well.
  4. Assassin Snails: Assassin snails are a killer species as their name suggests. They not only eat their own but also other snails, their eggs, and small newborns as well. Meaning that they are a perfect choice for getting rid of large infestations of the Bladder Snails from your tank.
  5. Crayfish: Crayfish are also a great species that you can keep in the same tank with the Bladder Snails. Crayfish eat everything small, especially the eggs of the Bladder Snails and the newborn snails. So, it will help you keep the large snails alive in your tank to provide a perfectly balanced ecosystem and help you prevent an infestation of the Bladder Snails in your tank.


The size of these snails is very small. The average size of the Bladder Snail shell is about ½ inches. Meaning that they are one of the smallest aquarium species of snails. Most people confuse them with pond snails, but they are a completely different species with different size variations, shell types, and colors in the shell. The Bladder Snails are visually a beautiful and appealing snail species and that is one of the reasons why many fish keepers want them in their tanks.

Bladder Snails have one of the thinnest shells, with translucent coloration. They have a yellowish-gray shell with golden spots on different covering most of the shell. As they are transparent, you can see the internal organs of the snail from its shell. The flesh of the snail is what gives it the grayish look from inside. The outer walls of the snail body, known as the mantle, are colorful and have multiple brown-gold spots.

The shell of this snail has four to five whorls and an egg-like shape with a defined tip from where the snail exerts its body outside for motion and feeding. When its head is outside the shell, its small tentacles can be observed easily. These tentacles contain eyes and other sensory organs which help this snail navigate and look for food inside the tank.

Difference Between Pond Snails and Bladder Snails:

If you are not aware of the differences between pond snails and Bladder Snails, you might get confused while identifying them. Identifying them will help you know better about them, and what care guidelines you should follow as both of these have different requirements for living in aquariums. Here are the major differences that are easy to notice and can help you successfully identify them.

  • Pond Snails are larger than Bladder Snails, which means it will be easy for you to identify based on size. If the snail in your tank is larger than ½ inches, it is most likely a pond snail and not a Bladder Snail.
  • Shells are different in both species. The shell of a pond snail is opaque, while the shell of a Bladder Snail is translucent.
  • Tentacles are different. The pond snails have thick tentacles while the Bladder Snails have thin tentacles (thread-like).

These differences are easy enough to identify the species with the naked eye. This identification will help you take better care of the species with relevant guidelines.

Origin and Natural Habitat:

According to recent research, it was discovered that this species of snails originated from North America instead of the Mediterranean, as it was previously considered. It is one of the most common snail species in North America, Europe, and the United Kingdom regions. It has also been introduced in New Zealand.

This is an invasive species of snail that can live even in harsh conditions and survive. These traits helped this snail live in some of the harshest environments. It is found in lakes, ponds, rivers, canals, and waterways. It can survive water pollution, and extreme temperatures for a short time.

Bladder Snail Lifespan:

The lifespan of the Bladder Snails depends on their living conditions. If the living conditions are harsh and extreme, they can only live for a short period such as between 6 months to a year. But if the living conditions are perfect and balanced according to the needs of the Bladder Snails, it can live for more than two years. In the wild, they are born, they feed and reproduce once and die but under the perfect conditions in a tank, they can reproduce multiple times before dying.

Habitat and Tank Conditions:

As we discussed earlier, this species of snail is very resilient and can survive some of the harsh conditions. Meaning that you can put them in any tank and they would thrive. The main conversation here revolves around keeping them in check inside the aquarium. The Bladder Snails like clean, warm, and slow-moving slightly acidic water. Also, they live in the bottom layer of the tank and they spend most of their tank in that layer. They rarely reach the middle layer and live in the vegetation in this layer.

Tank conditions are simple for the Bladder Snail. Your focus should be on the bottom layer and the middle layer. Start by putting a lot of treated sand in the bottom layer as it would help create a perfect environment for them in the bottom layer. Apart from sand, you should also put cleaned substrate in the bottom layer. You can use rounded pebbles and stones to put in this layer. These conditions would depict the natural habitat of these creatures and would provide them a space to live.

Apart from the essentials (sand and substrate) in the bottom layer, you can also put vegetation, algae, and decorations in the bottom layer. These will provide them a hiding place in the bottom layer when they are being bullied by the large fish in the tank. For the middle layer, put a lot of vegetation in this layer as the Bladder Snails like to climb and reach the top of these plants. They do not eat the plants, so the plants in the bottom and middle layer would remain intact.

Calcium in Bladder Snail Tank:

The most important thing that you need to know about the care of these snails is that they need a lot of calcium. Calcium is the main ingredient in their shells and they need it to make these shells. So, if your tank environment has less amount of calcium, then your Bladder Snails would only grow to a small size and will reproduce less. It is also a control measure to control the population but it can also adversely impact the overall population as the extremely low level of calcium would kill the entire population of your Bladder Snails.

It depends on your requirements. If you want to keep the population of your snails, but want them to thrive in the aquarium, provide them with more calcium. But if you want to control the population, you can limit the supply of calcium in the water and it would cause distress in the snails. Meaning that the overall reproduction rate would drop and it would be easy for you to manage the population and ecosystem of your aquarium. Also, in the lack of sufficient calcium, the shells of these snails would become weaker and they would be easily killed by fish in the aquarium.

Water Conditions:

The Bladder Snails are a very durable species of snails. They can live in a variety of environments with different water conditions. For example, they can live in both soft and hard water. They can also live in slightly acidic to neutral waters with varying pH, mineral levels, temperature, and movement. Here are the water conditions that they prefer to live in.

  • Recommended water temperatures are 64°F to 84°F.
  • Recommended pH levels are 7.0 to 8.0.
  • Water hardness between  12 to 18 dGH (harder water).

Make sure to maintain the water conditions according to these recommended levels and the population of your Bladder Snails would thrive in your aquarium. But if you want to control the population, you can change these parameters and it would help you keep the population in check.

Water Source:

You can use any type of water for the tank of Bladder Snails. They do not have any specific water requirements, they can live in the water of any source. They would thrive even if you put them in a tap water tank, or an RO filtered water tank. As mentioned earlier, they are a durable species and can survive in more than one type of climate, and water condition.

Ideal Size For The Tank:

The ideal size of their tank depends on what type of fish you are keeping with them. For example, if you are putting the small fish species with the Bladder Snails, then you can use a small tank with more capacity. Apart from this, if you are introducing large fish species in your tank, you must choose a larger tank. A large tank is considered better because if you plan an expansion in the future, it would help you do that.

The size of the tank doesn’t impact the population of the snails as they are extremely small in comparison to fish and they can live in congested places, meanwhile the fish need proper swimming space. The minimum size of the tank is 20 gallons, but the recommended size for a healthy population of the Bladder Snail is anything larger than 20 gallons. A large tank would be able to hold a large number of snails and fish in your aquarium and would help you maintain a better balance in both populations.

Behavior and Temperament:

The Bladder Snail is one of the most peaceful aquatic species. They are social and peaceful, they connect with the other members of their family. It is one of their positive attributes which makes them attractive for many fishkeepers who want to fill their tanks with less aggressive or peaceful species of fish and snails. These are small and shy species of snails, they do not like confrontation at all.

So, if a fish approaches them, they would try to hide in the shell or would remain in a place where no fish can find them. Also, these are slow-moving species, and if you introduce them in your tank, they would immediately hide and you wouldn’t notice their presence for a long time until they feel comfortable in the tank. They spend most of their time hiding, eating, and climbing the grass and vegetation inside their tank.

Breeding Bladder Snail:

It is one of those species that can replicate in large numbers without any outside help. Once they are introduced in the tank, the conditions in the tank are safer and favorable for their growth. They would start to spawn and would replicate in numbers. Each Bladder Snail has both male and female sex organs and that is why they are known as hermaphrodites. The hermaphroditic animals are the ones that do not need a partner to reproduce as they carry both male and female sex organs. It provides them a perfect way to reproduce in large numbers from just a single snail. 

All they need is perfect conditions for their growth and once they reach a mature age, they would spawn and internally fertilize and create a new population from just one snail. But it happens in those conditions where there is no other snail around. But if there are more snails around, they would replicate normally. One snail would act like a female and the other would act like a male.

The eggs of the Bladder Snails are small and encapsulated. Each time they lay about 10 to 40 eggs. Vegetation and plants inside water help them hide their eggs from predators as most of the small fish species feed on their eggs. They protect these eggs by hiding them under the leaves of the plants. If there is no vegetation in the middle layer, they would lay these eggs on the bottom layer of the tank. These eggs take about 6 to 8 days to hatch and small snails come out of these eggs.

Small Bladder Snails that are newborn are also attacked by the fish in the aquarium. So, most of them would die immediately in the presence of predator fish species. But some would survive and live in the tank to reproduce once again. You will have to use the same food that you are feeding the adult snails for them as well.

Diet of Bladder Snail:

Bladder Snails are omnivorous species that mostly eat algae, but they also eat a lot of other things that they can find in the water. For example, they feed on the decaying matter inside your tank. It helps you keep your tank clean naturally. They also eat any food leftover from the fish that they could not finish. These snails eat everything such as meat, flakes, algae, and small insects.

You will not have to add anything special in your tank to feed your Bladder Snail population. Just add an extra amount of food that you were feeding your fish, and they would eat it. Because of this varied diet, they are capable of surviving not only in the wild conditions but also in the aquarium tanks. Also, feeding them extra would help them thrive and that is not a good thing for your aquarium. So keep the amount of food limited as it would help you lower the spread of their population so it is easy for you to intervene and control the number of snails in your tank.

Diseases of Bladder Snail:

There are a lot of diseases that can kill your entire population of Bladder Snails. But for most of them, these snails have developed internal immunity and you will not have to worry about that. The only thing that you will have to worry about is that these snails are capable of transferring their diseases to other members of the aquarium.

So, they can be a carrier of the disease that can infect and kill the entire population of fish in your aquarium. That is why make sure that you always add healthy and clean specimens in your tank and avoid putting any diseased Bladder Snail. Also, maintaining the temperature and water conditions would help you avoid the loss of your snail and fish population.

Is Bladder Snail a Saltwater or Freshwater Species?

The bladder Snail is a freshwater species, found in North America, the Mediterranean, Europe, and the United Kingdom.

Conclusion – Is Bladder Snail Suitable For Your Aquarium?

Well, the answer to this question is not that simple. You need to know about a few things first before answering this question. First of all, it is a personal choice for everyone to have bladder snails in their aquariums. Secondly, the number of snails, size of your tank, and the number of fish in the tank would determine if you should add any snails in your tank or not and if they would be suitable or not.

For example, if your tank is small, and all the fish are peaceful. Then you should not introduce the snails in such an environment, because it will be a perfect environment for their population to bloom. Once that happens, your entire ecosystem in the tank would be destroyed and imbalanced. Third, if your tank has snail-eating fish species that can keep their population in check, and prevent a population boom and you want to see these creatures in your tank, then Yes, these are suitable for your tank.


Question: Are Bladder Snails good or bad?

Answer: It depends on your point of view. If you are afraid of their population blooming habit and focus on their negatives for the aquarium then they are a bad choice, but if you look at their positives, such as being a natural cleaner in tanks and a beautiful species, then they are a good choice.

Question: What are the benefits of Bladder Snails?

Answer: The main benefit of having the bladder snail in your aquarium is that they are a natural cleaner of the environment. They eat decaying matter in the tank, and also the leftover food of the other fish species. Meaning that you will not have to work on cleaning the tank. Apart from this, they are also a beautiful species and have a colorful appearance. That is why many fishkeepers like having them in their fish tanks.

Question: How to control the Bladder Snail population?

Answer: There are a lot of measures to help you control the population of Bladder Snails. You can control the population by introducing predator fish species that eat their eggs and babies, and also mature snails. Apart from this, lowering the amount of calcium in their aquarium would cause them to reproduce less and would make them weak. That means they will be an easy snack for the fish. These are the measures that can help you control the spread of the Bladder snail population.

Question: Are Bladder Snails asexual?

Answer: Yes, the Bladder Snails are asexual invertebrates. They are hermaphroditic, meaning that they have both sexes and can behave like male and female separately and also at once. 

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