Physella accuta
Bladder Snail
Also incorrectly known as Pond snail
Bladder snails often get a bad reputation as pests, however, when properly cared for they can be awesome little pets and can be a great indicator if you are overfeeding your tank as they will reproduce rapidly. They can live up to 2 years depending on water parameters and care level and they can grow up to 1.5cm. They also don't have a defensive operculum, trap door that seals the shell closed like apple snails, leaving them unprotected.
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Identification​
The bladder snail has a hard translucent shell which unlike most spirals to the left they have very distinct gold 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 patterns. See chart at the bottom of page for differences between bladder and pond snails.
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Tank Requirements
Bladders require a tank size of at least 10L for a small group. They can be kept with almost any friendly community fish.
When adding to a tank stocking numbers should be kept into consideration. They make a great addition to a nano tank with a single Pomacea diffusa however the larger P.canaliculata have been known to suck them right out of the shell and swallow them whole.
They also must not be kept with fish that can fit bladders in their mouth as they may try to eat them. They can be sensitive to fish medications and salt and copper is toxic to them.
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Water Parameters
Always make sure your aquarium is cycled before adding any aquatic life and keep in mind adding too many at once could overload the cycle.
Temp: 18C (64f) to 28C (84f)
PH: 6 - 9
KH or Hardness: 6 -9
Calcium can be added to water to benefit shell health.
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Diet & Supplements
Bladders will consume algae, microbial biofilms and detritus, but to keep them healthy their diet should include added plant matter, calcium and protein.
Many prepared fish foods are good including vege wafers/pellets but they often do not contain enough calcium to sustain healthy growing shells in large groups, so it will most likely need to be added. One way to do this is to feed vegetables high in calcium.
They enjoy left over fish food, algae wafers or pellets and vegetables or a complete food like Snello.
They will also not eat living plants unless provided no other food.
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Anatomy
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Reproduction
Bladder snails, like other asexual invertebrates, often choose to behave as one sex or the other. Since they are hermaphrodites, they can switch to behaving like the other sex, or fill both roles.
As hermaphroditic freshwater snails, bladder snails have a sperm storage organ; the possession of both male and female reproductive organs allows them to reproduce through both internal self-fertilization and through cross-fertilization (mating).
If a bladder snail doesn’t find a mating partner, they will self-fertilize internally, particularly if they feel threatened and want to propagate before getting killed. Self-fertilization is not ideal as the resulting offspring have a lower survival rate. Even without feeling threatened, a bladder snail will resort to self-fertilization after eight weeks of not finding a mate.
Most bladder snails, however, choose the more traditional method of breeding. Bladder snail couples will usually mate strait away upon entering an aquarium. One bladder snail climbs onto the shell of another and crawls to the female reproductive organ, a process that can last a half-hour.
Somewhere between 28 and 42 days of life, a bladder snail reaches female maturity; male maturity occurs before that. The bladder snails are about half a cm long at the point that they reach sexual maturity.
Gender preference in a bladder snail can switch even in the middle of a breeding session.
Bladder snails lay capsules of eggs; each capsule holds 10-40 eggs and the eggs hatch 6-7 days after being laid. The eggs are transparent, and 70-90% hatch into baby bladder snails that are about 1 mm long.
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Pros & Cons
+ Good at removing decomposing plants and animals
+ Biodiversity in your aquarium
+ Suitable for most aquariums
+ Easy to care for
+ Will not eat most live plants
+ They're extremely hardy
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- Multiply rapidly if overfed
- Difficult to completely eradiate
- They lay eggs on decor
- They can produce young with or without a partner
- Shells can get lodged in some types of filtration
