Asian clam
The only bivalve in this catalogue, and one of the most costly freshwater invaders in the world — it blocks industrial water intakes at a scale measured in millions. In an aquarium it filters the water continuously and dies invisibly, which is the problem with keeping it.
Quick profile
- Scientific name
- Corbicula fluminea
- Adult size
- 2–4 cm (0.8–1.6 in)
- Lifespan
- 1–4 years
- Temperature
- 15–28 °C (59–82 °F)
- pH
- 7–8.5
- Hardness
- 8–25 °dGH
- Minimum tank
- 60 L (16 US gal)
- Minimum length
- 60 cm
- Swimming zone
- Bottom
- Social
- Tolerant of any grouping
- Diet
- Filter feeder
- Overall confidence
- moderate confidence
What keeping this species involves
Almost impossible to feed adequately in a clean aquarium, and a dead one decomposes buried in the sand where nobody sees it until the water goes wrong.
Sandy and gravelly beds of rivers and lakes with some current.
Identity and names
- Common name
- Asian clam
- Scientific name
- Corbicula fluminea
- Family
- Cyrenidae
- Order
- Venerida
- Class
- Bivalvia
- Also sold as
- golden clam, Corbicula fluminea, prosperity clam
Adult size and growth
2–4 cm (0.8–1.6 in) — Shell length.
Typical lifespan in an aquarium: 1–4 years. Almost every animal sold in a shop is a juvenile, so the tank has to suit the size in the first line rather than the size in the bag.
Shape, which is what the compatibility engine reads instead of length alone: globose with a grazing or sucking mouth. Assigned from what is typical of Cyrenidae, not examined for this species.
Water and tank requirements
A filter-feeder needs a bed of sand to sit in and enough water volume to carry food past it; the footprint is the sand bed.
Temperature (°C)
Scale: 0 to 36 °C.
pH (pH)
Scale: 4 to 9.5 pH.
Hardness (°dGH)
Scale: 0 to 30 °dGH.
Why these ranges: A wide band matching a species that has established across most temperate and subtropical fresh water on earth. Hardness is the requirement that matters, because a bivalve builds a great deal of shell.
Where these figures come from
Habitat class
Temperate still water
Ponds, lakes, canals and slow rivers outside the tropics, with a genuine winter.
The temperature range is the point. These animals experience a seasonal cycle, and keeping them at a constant tropical temperature shortens their lives without ever looking like the cause.
- Conductivity
- 150–800 µS/cm
- Flow
- still
- Dissolved oxygen
- variable
- Seasonality
- strong
These are figures for the KIND of water body, not measurements of this species. They are AquariumHQ’s summary of the general limnology and are given wide because the water is.
- TemperatureReasoned on this record
- This record states its own reason for this band. See the water section.
- pHReasoned on this record
- This record states its own reason for this band. See the water section.
- General hardnessSet by a requirement of the animal
- Hardness here is a shell requirement, not a habitat statement. A snail or mussel builds and repairs aragonite continuously, and in water without dissolved calcium the shell erodes faster than the animal can replace it — visibly, at the apex first. The band is therefore set by what the animal has to take out of the water rather than by what its river happens to contain, and several of these species are recorded from water considerably softer than the band advises.
| Requirement | Value | Notes |
|---|---|---|
| Temperature | 15–28 °C (59–82 °F) | Stability matters more than hitting an exact figure. |
| pH | 7–8.5 | A stable pH outside the ideal band is usually better than an unstable one inside it. |
| General hardness | 8–25 °dGH | Check your supplier's published figure before choosing species. |
| Minimum volume | 60 L (16 US gal) | A floor, not a recommendation. |
| Minimum footprint | 60 cm long | A filter-feeder needs a bed of sand to sit in and enough water volume to carry food past it; the footprint is the sand bed. |
| Water flow | moderate | Match the outflow to this rather than to the filter's rating. |
| Lid required | Recommended | Reduces evaporation and prevents accidents. |
| Structure | A deep bed of fine sand it can bury into, with current. A bare or gravel bottom gives it nowhere to sit. |
Behaviour
- Buries into sand with only the siphons exposed and filters continuously.
- Closes and stops filtering when conditions deteriorate, which makes it look alive for some time after it is not.
Feeding
Filters continuously and cannot be target-fed. A well-filtered tank starves it, which is the ordinary outcome of keeping one.
- Diet type
- Filter feeder
- Staples
- Suspended particles and phytoplankton, Green water, Powdered filter foods
Breeding
- Strategy
- Hermaphroditic, brooding larvae in the gills and releasing juveniles
- Difficulty
- incidental
- Parental care
- bearer
Self-fertilising, so a single clam can found a population. This is a large part of why it establishes so effectively.
Tankmates and compatibility
Assessments are derived from stored traits by the compatibility engine, with the reasoning shown. A verdict is a statement about probability, not a guarantee — individual temperament can override it.
| Towards | Risk | What it means |
|---|---|---|
| Small fish | none | Anything that fits in the mouth is at risk once this species reaches adult size. |
| Adult dwarf shrimp | none | Cover reduces losses but rarely prevents them where the risk is high. |
| Shrimplets | none | Determines whether a shrimp colony can grow rather than merely persist. |
| Snails | none | Applies to snails you wanted as well as snails you did not. |
| Long or trailing fins | none | Fin damage is an entry point for secondary infection. |
| Plants | none | Tough species such as Anubias and Java fern survive most grazers. |
Any pair in the catalogue can be assessed with the compatibility checker.
Welfare considerations
Points where the way this species is commonly sold or kept differs from what it actually needs.
- Starves slowly in an ordinary aquarium. Keeping one well needs green water or a pond, and most tanks provide neither.
- A dead clam buried in the substrate can foul a tank badly before it is found. This is the practical reason most keepers should not buy one.
- Among the most economically damaging freshwater invaders in the world through biofouling of water intakes. Never release it, and never empty tank water or substrate into a drain or a watercourse.
Problems to watch for
Most problems in a tank containing this species are general rather than species-specific. Start with the troubleshooting index and work from the observation rather than from a guess at the cause.
What AquariumHQ does not yet hold
Species-level disease susceptibility is modelled in the graph and is not yet populated. Health pages will not be published until each condition has veterinary sourcing, because health content written without evidence is the most harmful thing this product could publish. The gap is recorded in the coverage report.
Where it comes from
- Native range
- Native to eastern and southern Asia; introduced and established across the Americas and Europe
- Habitat
- Sandy and gravelly beds of rivers and lakes with some current.
What the checklists say
95 distribution statements retrieved from GBIF checklists. Establishment means is reproduced from the source where it states one, and left unstated where it does not — a record of presence is not a record of origin.
| Status | Places | What this means |
|---|---|---|
| Native | 1 | A checklist states the species occurs here naturally. |
| Introduced | 71 | A checklist states the species arrived here with human help. That is not a statement that it is established, harmful or illegal. |
| Recorded as invasive | 1 | A checklist states the species is invasive here. AquariumHQ reproduces that assessment; it does not make one. |
| Recorded as present, establishment means not stated | 22 | The source records the species as present and does not say whether it is native or introduced. AquariumHQ does not fill that in. |
Legal status and responsible practice
Restriction note
Established and regarded as invasive across much of North America and Europe, with movement or possession restricted in some jurisdictions. It is not among the species named on the EU Union list. AquariumHQ has not established the position in any named jurisdiction; check with the relevant national authority before acquiring or moving them.
Where this species has been introduced, and what followed
Two databases on two continents hold records for this species, and they are not two accounts of one event. They are separate introductions with separate causes, and the differences between them are the most informative thing on this panel.
North America
EstablishedFirst collected in 1938 on the Columbia River. NAS records the traditional account — that it entered as a food item — as lacking direct evidence, and offers arrival with imported Pacific oysters as an alternative. The mechanism of dispersal within North America is recorded as unknown.
- Arrived with a shipment of something elseThe organism was not the thing being shipped. Snails on aquarium plants, clams in shellfish consignments, apple snails in farmed crayfish.
- Deliberate stockingSomebody put the species into open water on purpose, for food, angling, ornament or mosquito control — frequently a government agency, and frequently before anyone considered the consequences.
- Route not establishedThe species is established outside its native range and how it got there has not been determined. Recorded as a gap rather than filled with the likeliest guess.
What has been established
- Biofouling of pipes and structuresReported in the literatureThe most prominent effect has been biofouling of power plant and industrial water systems, irrigation canals and pipes, and drinking water supplies. In the USA it has caused millions of dollars of damage to intake pipes.USGS Nonindigenous Aquatic Species database credits: Isom et al. 1986; Williams and McMahon 1986
- Physical alteration of habitatReported in the literatureAlters benthic substrates and competes with native species for limited resources.USGS Nonindigenous Aquatic Species database credits: Sickel 1986; Devick 1991
USGS Nonindigenous Aquatic Species database · Species Profile — Means of Introduction; Species Profile — Impact of Introduction · read 2026-08-29. A United States database: the routes and effects recorded here are the ones documented there, and say nothing about other regions.
Europe — recorded in 29 countries, first in Portugal in 1978
EstablishedEight pathway entries, two of them the aquarium trade and two live bait, both flagged MEDIUM uncertainty, alongside food contamination, animal contamination, habitat material and ballast water. EASIN is describing a species that arrives by every route available to a small bivalve and is not confident which mattered most.
- Deliberate aquarium releaseSomebody took the animal out of a tank and put it into open water. The commonest reason is that the fish outgrew the aquarium, which is why size at maturity is a conservation question as well as a welfare one.
- Bait-bucket release by anglersAn angler empties an unused bait bucket at the end of a session. Documented as the primary route for several crayfish and small fish, and almost entirely absent from the aquarium hobby's account of the problem.
- Ballast water or hull foulingLarvae carried in a ship's ballast tanks and discharged in another continent's fresh water. Nothing to do with aquariums, and the route behind two of the most consequential freshwater invasions on record.
- Arrived with a shipment of something elseThe organism was not the thing being shipped. Snails on aquarium plants, clams in shellfish consignments, apple snails in farmed crayfish.
What has been established
- Altered nutrient cyclingMeasured in studyRated HIGH against clean water and HIGH against inland waters. Corbicula filters at very high densities and shifts nutrients from the water column to the sediment, which changes what the water body supports.
- Biofouling of pipes and structuresMeasured in studyRated HIGH against energy and HIGH against industry. Clam beds block intake pipes at power stations and water treatment works, and this is the impact that gets it counted.
- Competition with native speciesMeasured in studyRated HIGH against nature protection and restoration, principally against native unionid mussels.
EASIN — European Alien Species Information Network · EASIN catalogue record R04013 (apixg/catxg) · read 2026-08-30. A European network: the routes and effects recorded here are the ones documented in Europe. EASIN compiles national inventories, DAISIE and CABI rather than measuring, and its pathway assignments carry its own uncertainty flags, which are reported above where it sets them.
Never release aquarium life into the wild
Aquarium animals, plants, and aquarium water must never be released into ponds, rivers, canals, drains or the sea — not even in a country where the species is sold freely. Released fish and invertebrates establish populations that displace native species, and released plants and water carry pathogens, parasites and fragments capable of spreading without any animal at all. If you can no longer keep an animal, rehome it through an aquarium society, a retailer that accepts returns, or another keeper.
- Rehome through a local aquarium society, a specialist retailer or another keeper.
- Unwanted plants go in household waste or a hot compost heap, never in a watercourse or a garden pond.
- Never empty a bucket of tank water into a drain that discharges to open water.
- If an animal is beyond rehoming, ask an aquatic veterinarian about humane euthanasia rather than releasing it.
Legal status is recorded from the sources named and was correct on the verification date shown. Rules change, and sub-national rules often differ from national ones. Check the current position with the relevant authority before acquiring, selling or moving any animal or plant.
Evidence
Every stored value with the kind of support behind it and where to check it. Evidence type and confidence are separate axes: an editorial position held confidently and a measurement held tentatively are different things.
| Claim | Value | Evidence type | Confidence | Source |
|---|---|---|---|---|
| scientific name | Corbicula fluminea | Observed / measured | high confidence | Catalogue of Life; GBIF — Global Biodiversity Information Facility |
| native range | Native to eastern and southern Asia; introduced and established across the Americas and Europe | Observed / measured | moderate confidence | GBIF — Global Biodiversity Information Facility |
| adult size | 2–4 cm | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| lifespan | 1–4 years | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| temperature | 15–28 °C | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| ph | 7–8.5 pH | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| general hardness | 8–25 °dGH | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| minimum tank volume | ≥ 60 L | AquariumHQ editorial position | moderate confidence | AquariumHQ husbandry synthesis |
| minimum tank length | ≥ 60 cm | AquariumHQ editorial position | moderate confidence | AquariumHQ husbandry synthesis |
Last reviewed 2026-08-10. Values labelled as an aquarium-literature consensus are AquariumHQ editorial positions rather than measurements — see how evidence is handled.
Why we say this
What each figure on this page rests on, and how far that is from being independently established.
Every figure on this page has a provenance. Open any claim to see what AquariumHQ holds for it, which sources say what, and what a claim of that kind actually needs. Different claims need different evidence: an accepted scientific name is settled by one authority, while a legal restriction needs a current primary instrument. A single source is often the right answer rather than a thin one.
scientific nameAquariumHQ's own position, externally checkableBased on a verified authoritative source.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: accepted scientific name and classification — 1 authoritative source in an appropriate context. Checked against gbif on 2026-08-13. One authoritative backbone is what this class requires.
What would improve this: Go and read a source. This is reachable and has not been reached.
native rangeAquariumHQ's own position, externally checkableBased on a verified authoritative source.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: where the species occurs — 1 authoritative source in an appropriate context. 95 distribution statements held from GBIF checklists — native in 1, introduced in 66, recorded invasive in 1 countries. Establishment means is reproduced from the source, never inferred from occurrence.
What would improve this: Go and read a source. This is reachable and has not been reached.
adult sizeAquariumHQ's own position, externally checkableAquariumHQ's own position, derived from evidenced inputs.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: size a well-kept specimen reaches — no external source is required, provided AquariumHQ shows its reasoning. No external source is required for this class. AquariumHQ's position stands on its stated reasoning.
What would improve this: Go and read a source. This is reachable and has not been reached.
lifespanAquariumHQ's own position, externally checkableAquariumHQ's own position, derived from evidenced inputs.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: what aquariumhq advises for keeping — no external source is required, provided AquariumHQ shows its reasoning. No external source is required for this class. AquariumHQ's position stands on its stated reasoning.
What would improve this: Go and read a source. This is reachable and has not been reached.
temperaturePublished with one end of the range missingAquariumHQ's own position, derived from evidenced inputs.
A source published one end of the range and left the other unstated.
No more than 34 degC — the source does not state a lower boundNAS reports mass mortality above 34 degC in heat waves, and separately that a population in power-station cooling water survived 38 degC. Those two figures are not the ends of one range — they are a field observation and a thermal-refuge exception — so no range is recorded from them.
What this kind of claim needs: what aquariumhq advises for keeping — no external source is required, provided AquariumHQ shows its reasoning. No external source is required for this class. AquariumHQ's position stands on its stated reasoning.
What would improve this: Find a source that publishes the missing bound. Do not infer it.
phAquariumHQ's own position, externally checkableAquariumHQ's own position, derived from evidenced inputs.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: what aquariumhq advises for keeping — no external source is required, provided AquariumHQ shows its reasoning. No external source is required for this class. AquariumHQ's position stands on its stated reasoning.
What would improve this: Go and read a source. This is reachable and has not been reached.
general hardnessAquariumHQ's own position, externally checkableAquariumHQ's own position, derived from evidenced inputs.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: what aquariumhq advises for keeping — no external source is required, provided AquariumHQ shows its reasoning. No external source is required for this class. AquariumHQ's position stands on its stated reasoning.
What would improve this: Go and read a source. This is reachable and has not been reached.
minimum tank volumeAquariumHQ's judgement — no authority publishes thisAquariumHQ's own position, derived from evidenced inputs.
No external authority publishes this. The rationale carries the reasoning.
What this kind of claim needs: minimum tank size — no external source is required, provided AquariumHQ shows its reasoning. No authority publishes this. AquariumHQ derives it, and the derivation is recorded with its inputs and assumptions.
What would improve this: Keep the rationale current. There is no source to find.
minimum tank lengthAquariumHQ's judgement — no authority publishes thisAquariumHQ's own position, derived from evidenced inputs.
No external authority publishes this. The rationale carries the reasoning.
What this kind of claim needs: minimum tank size — no external source is required, provided AquariumHQ shows its reasoning. No authority publishes this. AquariumHQ derives it, and the derivation is recorded with its inputs and assumptions.
What would improve this: Keep the rationale current. There is no source to find.
Guides relevant to this species
Chosen from this record's own traits rather than listed on every page.
- Native, introduced and invasiveThis record carries an invasive or legal note, and those are five separate claims that are easy to read as one.
- Wild conditions and aquarium recommendationsThe water band on this page is an AquariumHQ position with a stated reason, not a measurement of a river.
- How aquarium species get into the wildThis species has a documented introduction outside its native range, with the route recorded.
Group size and social behaviour
Sessile once settled and entirely indifferent to everything.