Bladder snail
Physella acuta
The bladder snail (Physella acuta) is a small freshwater snail that often arrives unnoticed with aquarium plants. It grazes algae and detritus and can take air at the water surface. It reproduces quickly; laboratory research shows that even an isolated animal may lay eggs. That does not make it an automatic cleanup solution or a suitable deliberate purchase for every aquarium. Manage any population consciously, and never release snails, eggs, plants or aquarium water into natural waters or drains.
Plan your aquarium →At a glance
- Temperature
- 18–28 °C
- pH
- 6.5–8.0
- Diet
- detritivore
- Adult size
- Up to 1.6 cm
- Temperament
- Peaceful
About this species
Physella acuta (Draparnaud, 1805) belongs to the family Physidae. MolluscaBase/WoRMS currently uses this name; older literature often uses Physa acuta and sometimes Haitia acuta. Names such as Physella heterostropha and P. integra have been treated as synonyms in taxonomic revisions. Small bladder snails can resemble one another, so a casual sighting cannot always be identified from the shell alone.
Natural habitat
The species is native to North America and has become established elsewhere through human transport. It occupies varied freshwater habitats, including ponds, lakes, streams, ditches and artificial waters. Aquarium plants and the aquatic trade are recognised spread routes. It breathes air with a lung and may visit the surface; this is normal behaviour and does not by itself prove the water lacks oxygen.
Aquarium and layout
No responsible universal minimum tank volume is established. The snail is often an accidental resident of an existing aquarium and can survive in many setups; that does not make every tiny jar suitable housing. Provide stable, clean water, surfaces with biofilm and an unobstructed route to the surface. Excess feeding and decaying organic matter can worsen water quality and population control.
Water conditions
Aquarium sources publish widely differing ranges. As a practical overlap, this guide gives about 18–28°C and pH 6.5–8; these are hobby-care values, not experimentally established species limits or an optimum. The reviewed sources do not agree on a reliable GH/KH target or minimum volume. Keep conditions stable and test ammonia/ammonium and nitrite if animals decline. Do not infer ideal care from records in polluted outdoor water.
Behaviour and group size
The snail moves across glass, plants, wood and other surfaces, grazing on algae, biofilm and organic matter. It may travel along the surface or take in air there. It is small and does not require a school. A rising number may indicate abundant food, but it is not a precise water-quality test; assess the aquarium directly.
Feeding
Biological species accounts report algae and detritus in its diet; aquarium sources also mention biofilm, soft algae, decaying plants and leftovers. No reviewed source establishes a branded food as necessary daily feeding. Reduce uneaten fish food and remove decaying matter rather than feeding extra to grow the snail population. The snails do not replace filter care or water changes.
Breeding
Physella acuta is hermaphroditic. Research describes mating and successful self-fertilisation when an animal is isolated. Laboratory populations matured in about 6–8 weeks, and adults sometimes laid 50–100 eggs per week; that is not a prediction for a home aquarium. Eggs form a clear gelatinous mass on firm surfaces. Inspect plants and glass if you want to limit population growth.
Keeping with fish
No controlled evidence establishes a universally safe pairing with every fish. Small peaceful fish may ignore the snail, while snail-eating fish may consume it. Consider adult size, hunting behaviour, mouth size, food competition and grazing space. An untested combination is not presented here as proven safe or trialled.
Keeping with other invertebrates
No controlled, species-specific cohabitation trial with another aquarium invertebrate was found. Food competition and predation can vary by aquarium; some crayfish, crabs and snail-eating invertebrates may attack small snails. Treat water values only as an initial screen and observe animals after introduction. No unverified exact pairing is recommended as safe.
Exoskeleton, shell and minerals
Check the shell for new erosion and observe whether the snail moves and attaches normally. Shell changes can have several causes; do not alter hardness or pH blindly. First test water and look for recent changes. Algae or snail treatments may also harm other invertebrates. Check the label and effects before choosing a treatment.
Possible problems
The main practical concern is rapid reproduction, especially where food leftovers and organic waste remain available. Reduce excess feeding and remove egg masses or snails manually if needed; rehome surplus animals with another aquarist. Do not use salt, copper or other chemicals as a routine fix. Never release snails, eggs, plants, water or filter material into ponds, drains or the wild. The species is invasive in many areas outside its native range.
Suitable plants
Dwarf Anubias
Conditional: Physella acuta grazes algae and periphyton on submerged surfaces, so leaves may also be used as grazing surfaces. No trial with this snail and Anubias specifically was found. Check tender or new leaves for damage and attach Anubias to wood or stone if useful. This is a cautious practical assessment, not a guarantee that all plants are safe.
- Light
- Low, Moderate
- CO₂
- CO₂ injection not needed
Sources & review
This care guide draws on several specialist sources and was last checked on .
View the sources
- MolluscaBase / WoRMS — Physella acuta (Draparnaud, 1805)
- GBIF Backbone — Physella acuta
- Lucid Central — Physa acuta — Australian Freshwater Molluscs identification key
- Freshwater Gastropods of North America — Species Account: Physa acuta
- MolluscIreland — Physella acuta
- U.S. Geological Survey Nonindigenous Aquatic Species Database — Acute bladder snail — Species Profile
- FishFish — Escargot physa acuta (physella acuta)
- Die Wasserwelt — Blasenschnecke (Physella acuta)
- AquaGuide — Physella acuta — Guide d’élevage
- Wikimedia Commons / Dat doris — Blasenschnecke 03.jpg
- Peer-reviewed research, Freshwater Biology — Resource distribution and internal factors interact to govern movement of a freshwater snail
- Environmental Science & Technology, peer-reviewed research — Herbicide-Induced Shifts in the Periphyton Community Composition Indirectly Affect Feeding Activity and Physiology of the Gastropod Grazer Physella acuta