Understanding Bladder Snail Behavior and Lifestyle

bladder snail with a pea puffer inside aquarium
Photography: @weddellsam

Bladder snails usually popup in an aquarium, and in a few weeks, they can multiply and make their presence felt, mainly by their remarkable breeding speed and you’ll start to see everywhere speeding around (for a snail!).

These creatures have a unique trait that sets them apart from other snails: their shells spiral to the left! Interesting, right?

Bladder snails were equipped with the interesting ability to shake off leeches and other problematic crawling organisms that may be hitching a free ride on their backs. So in aquariums, you might see these snails sometimes violently shaking their shells to unload a hitchhiker!

Some have also been reported to be able to take in air and actually float around the tank like a hot air balloon! (this is a less common behavior in aquariums with more water flow; snails in tanks with sponge filters often exhibit this unexpected behavior).

For the aquarists who are willing to take a closer look at the notorious, oddball bladder snail, one might just find it to be one of the most interesting additions to any well-maintained tank


SubTypesMoss bladder snail (Aplexa hypnorum)
Acute bladder snail (Physella acuta)
RelativesPhysella heterostropha
Physella gyrina
SizeAbout ½ inch overall
Lifespan3-5 years
Preferred waterFreshwater, pH 7-8 hard water
Tolerates acidic deoxygenated water
Temperature64-84 degrees Fahrenheit
DietAlgae and decaying plants


Bladder snails don’t have a distinct origin, some theories claim that they were first found in Eastern Europe while others demonstrate that they started in Central America and spread from there to the rest of the world.

Bladder snails are found in warm freshwater where they prefer standing ponds, but they fair nicely in slow-moving streams too. However, they can also survive at the banks of larger lakes.

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Usually, a few bladder snails wouldn’t cause a problem because they can be helpful to clean up the rotting remains from the aquarium. Some breeders also keep them in a separate aquarium to use as food for other fish.


bladder snail inside aquarium
Photography: @lpond22

The bladder snail has a hard translucent shell with very distinct golden markings on a yellow background.

The shell is mostly round with a right mantle lobe and an apex at its rear end. The color of the snail is dark with a mixture of black, grey, and purple lace-like patterns. 


Planted tank
Photography: @lpond22

Bladder snails are rarely brought into an aquarium intentionally, they usually get into an aquarium by latching on to plants or their eggs are caught in the same net with other coveted pet fish.

Once they arrive in an aquarium, they hide for a few days under the gravel and then foray outside to feed and explore.

Bladder snails move at a remarkable speed and they have a conspicuous form, so they’re hard to miss.

They also multiply actively and enthusiastically, often completely on their own while not necessarily needing a mate from the opposite sex.

Do Bladder Snails Eat Plants?

One of the most common questions by aquarists, especially ones with meticulously-trimmed and aquascaped tanks, is whether or not a bladder snail will ruin aquatic plants indiscriminately. Unfortunately, however, there is no straight yes or no answer here; it’ll depend on the type of environment your aquarium has.

Bladder snails developed a preferred menu consisting mainly of decaying plant matter and algae in their natural habitat of standing water and swamps.

Sometimes in the wild a snail pond dries up caused by seasonal or human intervention, and in that situation, the bladder snail runs off to the nearest decaying plant clump and feeds there. 

Bladder snails living in an aquarium follow the same general pattern of nibbling on decaying matter, but in that case, it’s mostly excess fish food.

If you keep a tightly-controlled tank with little-to-no scraps of food and algae for the bladder snail to munch on, then chances are, your snail will take a nibble from the decaying and/or softer leaves of your plants from time to time.

However, they rarely approach the aquarium plants and that’s why several fish breeders consider bladder snails as benign scavengers that just keep the biome clean. Provided they stay in controlled amounts of course. 

Controlling a Bladder Snail Infestation

Physella acuta inside an aquarium
Photography: @imperfect_nature_aquarium

If you find yourself having hoards of snails run over your plants, you may be doing one of the following:

  1. Feeding too much – fish love to beg for food, and aquarists often fall into the trap of overfeeding the fish. The problem with overfeeding is that not only will can fish end up getting obese, but they’ll also produce more fish waste, which is then consumed by both algae and plants.

    In tanks that have high levels of phosphate and nitrate this can be a problem as algae thrives in nutrient-dense tanks. The surplus of algae and uneaten food makes one’s tank a haven for large groups of bladder snails. Feed sparingly, and use high quality food to keep your tank’s water quality high and your bladder snail population low.

  2. Inconsistent Water Changes – related to overfeeding, inconsistent water changes allow waste to build up, therefore providing algae a suitable environment to grow in and thrive.

    Algae can easily outcompete plants for the necessary nutrients, and even block their leaves, therefore making them much weaker. Eventually, the snails and fish take a nibble or two from the wilting leaves from time to time, without the plant being able to heal and grow at a faster pace.

    This is dangerous, as tanks like these are often headed for a crash, and the burst of snail growth is a sign that one must take action soon before it’s too late.

Fortunately, if you’ve fixed problems 1 and 2, you should be easy to get rid of the excess snails you might still have in your tank. Here are some of the more popular ways of removing excess bladder snails:

  1. Setting up lettuce traps – the favorite vegetable of the bladder snail is romaine lettuce. This makes it easy for you to trap them; simply drop a romaine lettuce leaf at the bottom of the tank and collect the snails you don’t need.

    You can either drop them off at a pet shop or give it to someone who needs them (usually people who keep loaches or puffer fish).

  2. Buying bladder snail predators – you can also control a bladder snail infestation by introducing predatory creatures that see the bladder snail as a snack into your aquarium.

    Read on below to see what time of fish can help you solve this problem.

What Fish Eat Bladder Snails?

Bladder snails are the natural prey for some omnivorous or carnivorous fish. These predators mostly see a snail as a long-awaited yummy treat.

This behavior is consistent in the fish’s natural habitat. In an aquarium, however, fish could exhibit different behavior where it might ignore the snail and show interest in other types of food.

These are some of the fish that normally eat bladder snails:

Green Spotted Pufferfish

Green Spotted Pufferfish is originally from the fresh waters of southeast Asia where it’s well versed in waterbed hunting and has a special craving for hard-shelled snails. Munching snails is good for their jaw.

Green spotted puffers are pretty looking fish with a flaring temper. They aren’t very sociable and love to eat up their little neighbors.

They could tolerate having a mate around the aquarium but that’s not always going to be the case because a lot of the time they may just as well eat them up too.    

Betta Fish

Betta fish is another cruel beauty. It has an aggressive attitude that contrasts with its angelic shape and demeanor.

Betta fish like Green spotted puffer are an Asian freshwater fish that used to dwell in swamped rice fields.

Betta is a carnivore that’s often nicknamed siamese fighter, so it’ll eat bladder snails and pretty much any good protein.

Size matters though, and as it’s a small fish it’ll only approach the eggs and baby snails. 

Yoyo Loach Fish

Loach fish are freshwater sociable fish with a lovely demeanor and a huge appetite for bladder snails.

Yoyo Loach, got that funny name from the markings on their backs which spell a clear ‘yo-yo’. They’re generally nice towards the other fish in the aquarium but these snails are not very safe around them.

They occasionally act a little naughty, especially if there are five or six of them, and these playful episodes tend to disturb the other fish a little.

They’re also pretty large for aquarium fish as they can grow to 6 1/2 inches, which then requires a spacious aquarium for comfort and well being. 

Crayfish and Assassin Snails

These aren’t actually fish, crayfish is a crustacean and assassin snails are mollusks – but they’re common in an aquarium and they both have encounters with bladder snails.

Crayfish likes the taste of snails, but they can be a bit picky when it comes to shell hardness and size – this crustacean prefers smaller and softer snails.

Assassin snails don’t mind size much, and it’ll probably clean up a whole aquarium from a snail infestation. They like to hunt snails, but it’ll take its time though – you can’t rush talent. 

Crayfish and assassin snails are considered natural prey for other aquarium fish, so they might be eaten by a potential predator before they could handle the bladder snail issues.

Are Bladder Snails Asexual?

It’s common for invertebrates like worms and snails to be asexual, or hermaphrodite. They have both male and female reproductive syestems, but they normally choose to behave as one or the other.

The dating and courting patterns for bladder snails are quite typical of guy meets girl, until they find themselves completely single, then they try something else. 

A snail that finds itself alone in a pond or aquarium will start breeding on its own, it doesn’t have the patience to wait forever.

Usually, a couple of snails breed as soon as they land in an aquarium while a snail that believes there are no mates available would consider single parenthood after about 8 weeks.

Inbreeding isn’t the best option for snails, and hermaphrodite vertebrates in general, it’s the last resort because the offspring are often weaker and less viable than the parent.

The 8-week mark is cut off and shortened significantly if the snail feels threatened. That’s when survival kicks in and the bladder snail starts a family right away.


Bladder snails are quite peaceful creatures and they can enhance the wellbeing of the aquarium environment by constantly eating the scraps and keeping them from rotting and spoiling the water. However, do tend to procreate extravagantly and may need some active measures to keep their numbers in check.

Adding a natural predator that craves bladder snails is sometimes a good setup, but choosing the right fish could be challenging as they might show aggressive behavior towards the other fish. In addition to this caution, if you want to preserve some of the bladder fish population you will need to be careful how many predators you add as they may decimate the whole population.

Take these two points into consideration when do decide whether or not to add bladder snails into your aquarium.

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