SnailfreshwaterUndemanding

Island apple snail

A very large apple snail that eats aquatic vegetation at a rate that has removed it from entire wetlands, and which is among the most damaging introduced freshwater molluscs anywhere. It is banned across the European Union and is included here so that it can be told apart from the mystery snail.

Quick profile

Scientific name: Pomacea maculata
Adult size: 7–15 cm (2.8–5.9 in)
Lifespan: 2–4 years
Temperature: 18–30 °C (64–86 °F)
pH: 7–8.5
Hardness: 8–25 °dGH
Minimum tank: 80 L (21 US gal)
Minimum length: 70 cm
Swimming zone: All levels
Social: Tolerant of any grouping
Diet: Herbivore
Overall confidence: moderate confidence

What keeping this species involves

Hardy, fast-growing and prolific, which is the reason for the prohibitions rather than a recommendation.

Still and slow warm water with abundant vegetation: wetlands, canals, rice fields and lake margins.

Identity and names

Common name: Island apple snail
Scientific name: Pomacea maculata
Family: Ampullariidae
Order: Architaenioglossa
Class: Gastropoda
Also sold as: Pomacea maculata, Pomacea insularum, giant apple snail, channeled apple snail
Former or synonymous names: Pomacea insularum

Adult size and growth

7–15 cm (2.8–5.9 in)

Typical lifespan in an aquarium: 2–4 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 Ampullariidae, not examined for this species.

Water and tank requirements

Recorded for completeness. This is a species AquariumHQ does not recommend keeping, and across the European Union keeping it is prohibited outright.

Temperature (°C)

Island apple snail

18–30

Scale: 0 to 36 °C.

pH (pH)

Island apple snail

7–8.5

Scale: 4 to 9.5 pH.

Hardness (°dGH)

Island apple snail

8–25

Scale: 0 to 30 °dGH.

The bands AquariumHQ publishes for the island apple snail, each drawn against the full range this catalogue uses for that parameter. A narrow band on a wide scale is a specialist; a wide one is a genuinely tolerant animal. Source: AquariumHQ husbandry position for this record — an editorial range, not a measurement

Why these ranges: Warm South American and introduced tropical wetland water, generally hard. The species survives a very wide range, which is documented here rather than recommended.

Where these figures come from

Habitat class

Rice paddy, ditch and drain

Shallow, still, sun-warmed managed water — agricultural rather than natural, and now the primary habitat of a number of aquarium species.

Enormous daily and annual temperature swing, low oxygen and shallow water. Species from here tolerate far more than a tropical community setting suggests, and several of them do not want to be kept at 26 °C all year.

Conductivity: 80–500 µS/cm
Flow: still
Dissolved oxygen: low
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	18–30 °C (64–86 °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	80 L (21 US gal)	A floor, not a recommendation.
Minimum footprint	70 cm long × 35 cm deep	Recorded for completeness. This is a species AquariumHQ does not recommend keeping, and across the European Union keeping it is prohibited outright.
Water flow	low	Match the outflow to this rather than to the filter's rating.
Lid required	Recommended	Reduces evaporation and prevents accidents.
Structure	Access to the water surface for breathing and for laying eggs above the water line.

Behaviour

Extends a long siphon to the surface to breathe while remaining submerged, which is how it survives in poorly oxygenated water.
Leaves the water to lay bright pink egg masses on emergent stems, walls and equipment above the water line.

Telling males from females

Sexes are separate and are distinguished by the shape of the operculum and the mantle in mature animals. Females are usually larger.

Feeding

Eats living aquatic plants readily and in quantity, which is the mechanism behind its ecological impact and is also why it cannot be kept in a planted tank.

Diet type: Herbivore
Staples: Aquatic plants, Blanched vegetables, Algae

Breeding

Strategy: Large pink egg clutches laid above the water line on emergent surfaces
Difficulty: incidental
Parental care: none

Clutches contain hundreds to over a thousand eggs and are laid out of the water, which puts them beyond the reach of aquatic predators.

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.

Risk this species poses to common tankmates
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	consumes	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.

Frequently confused with the mystery snail, which is a different and much less destructive species. The pink egg clutch above the water line is the clearest identifying feature.
Where a clutch appears in an aquarium and the species is uncertain, removing and destroying it is the responsible action. Apple snails have established from aquarium releases in several regions.

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 the Paraná and Amazon basins of South America; introduced and invasive across Asia and the southern United States
Habitat: Still and slow warm water with abundant vegetation: wetlands, canals, rice fields and lake margins.

What the checklists say

18 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	14	A checklist states the species arrived here with human help. That is not a statement that it is established, harmful or illegal.
Recorded as present, establishment means not stated	3	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

Apple snails are restricted across the European Union at genus level, and the instrument is a plant-health measure rather than an invasive-species listing — the consolidated Union list under Regulation (EU) No 1143/2014 was read in full on 2026-08-29 and contains no Pomacea entry at all. The measure in force is Commission Implementing Regulation (EU) 2024/2013, and because it is drawn across the genus it catches the mystery snail as well as this species. In the United States the restriction comes from plant-pest law rather than from the injurious-wildlife listing, and several states prohibit possession outright. The position differs sharply between jurisdictions, so check the rules that apply locally before acquiring, selling or moving one.

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.

Southeastern United States

Established

Likely introduced via the aquarium trade, with southeastern United States populations traced genetically to native populations in Argentina and Brazil. The timeline is unclear because the species was initially misidentified as Pomacea canaliculata.

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.
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

Damage to crops or aquacultureReported in the literatureApple snails are known agricultural pests, feeding on rice crops and causing great economic damage. In 2018 a Louisiana farmer shut down a crawfish harvest because of apple snails that had entered flooded rice fields.USGS Nonindigenous Aquatic Species database credits: Cowie 2002; Hayes et al. 2008
Human health consequenceMeasured in studyThe rat lungworm Angiostrongylus cantonensis, a nematode that can cause eosinophilic meningitis in humans, has been detected in populations of this species in New Orleans.USGS Nonindigenous Aquatic Species database credits: Teem et al. 2013
Carries parasites or pathogensReported in the literatureFound hitchhiking in farmed crayfish shipments from Louisiana, which is now a subject of increased regulation.

The apple snail's pink egg clutches are laid above the waterline and are the reason a single escaped snail can seed a population. This is also the species behind the EU plant-health restriction on the whole genus.

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 — Spain from 2009, also recorded in Israel and Norway

Established

One pathway, no uncertainty flag: pet and aquarium species. The European invasion of the Ebro delta began with an apple snail out of a tank, and it is the case European apple-snail regulation was written around.

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.

What has been established

Damage to crops or aquacultureMeasured in studyRated HIGH against agriculture and HIGH against plant health. The animal eats rice seedlings, and the Ebro delta rice industry is the reason this became a policy question within two years of the first record.
Loss of aquatic plantsMeasured in studyRated HIGH against nature protection and restoration and against clean water. Removing the macrophytes from a wetland switches it from a plant-dominated clear state to an algal turbid one, and the switch is hard to reverse.
Human health consequenceReported in the literatureRated HIGH against human health. Pomacea species are intermediate hosts for the rat lungworm Angiostrongylus cantonensis. This is a real mechanism and it is a tropical-range concern rather than a European one; recorded because EASIN scores it, not because it is a European risk today.

Pomacea is subject to EU plant-health measures. AquariumHQ also holds a USGS NAS record for the United States invasion; the European one is a separate event with a separate cause.

EASIN — European Alien Species Information Network · EASIN catalogue record R19289 (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.

What AquariumHQ has recorded, by jurisdiction, with the instrument each entry comes from and how far the check went. Ecological risk and legal status are separate: a species can be ecologically risky and legally unrestricted, or restricted where it could never establish.

EU

Prohibitedimport

The EU restriction on apple snails is a plant-health measure rather than an invasive-species listing, and it is drawn at genus level across Pomacea. This species is the one the measure was principally aimed at: it is a serious agricultural pest of rice in its introduced range.

Instrument: Commission Implementing Regulation (EU) 2024/2013 of 23 July 2024 on measures to prevent the establishment and spread within the Union territory and to eradicate Pomacea (Perry), applicable from 26 January 2025

INDEPENDENTLY CORROBORATED, IN THE NEGATIVE. Mega Sprint 1 read the consolidated Union list of invasive alien species in full and found no Pomacea entry anywhere in it, which confirms from the primary source what Sprint 3 established by inference: the apple-snail restriction is not an invasive-species listing. The operative text of Regulation 2024/2013 itself remains unread, so what it requires in detail is still recorded as unknown.

Instrument recorded, species entry not re-checked · last checked 2026-08-29 · AquariumHQ has recorded the instrument and what it does, but has not re-confirmed this species' entry against the current consolidated text. Listings are amended, so treat this as a pointer to the right law rather than as a confirmation of the current position, and check with the authority before acting.

US

Restrictedimport

Apple snails are regulated as a plant pest at federal level in the United States, and importation and interstate movement of Pomacea are restricted. Several states prohibit possession outright. This species is absent from the injurious-wildlife listing at 50 CFR § 16.13, which was read in full on 2026-08-29 and covers no gastropod.

Instrument: USDA APHIS plant-pest regulation of Pomacea; state prohibitions in several states

Two federal regimes are in play and they are easy to confuse. The injurious-wildlife listing under the Lacey Act does not cover apple snails at all; the restriction comes from plant-pest law administered by a different agency.

GB

Prohibitedrelease

Release or escape of any non-native animal is an offence. Apple snails lay their egg clutches above the water line on emergent surfaces, which is how a population escapes a container that would hold an aquatic animal.

Instrument: Wildlife and Countryside Act 1981, section 14

Instrument recorded, species entry not re-checked · last checked 2026-08-11 · AquariumHQ has recorded the instrument and what it does, but has not re-confirmed this species' entry against the current consolidated text. Listings are amended, so treat this as a pointer to the right law rather than as a confirmation of the current position, and check with the authority before acting.

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	Pomacea maculata	Observed / measured	high confidence	Catalogue of Life; GBIF — Global Biodiversity Information Facility
native range	Native to the Paraná and Amazon basins of South America; introduced and invasive across Asia and the southern United States	Observed / measured	moderate confidence	GBIF — Global Biodiversity Information Facility
adult size	7–15 cm	Aquarium-literature consensus	moderate confidence	AquariumHQ husbandry synthesis
lifespan	2–4 years	Aquarium-literature consensus	moderate confidence	AquariumHQ husbandry synthesis
temperature	18–30 °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	≥ 80 L	AquariumHQ editorial position	moderate confidence	AquariumHQ husbandry synthesis
minimum tank length	≥ 70 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 2026-08-29. 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. 18 distribution statements held from GBIF checklists — native in 1, introduced in 14 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 sizeOne sourceAquariumHQ's own position, derived from evidenced inputs.1 citation, 1 independent origin

A single source: Pain 1960.

155 mm — USGS Nonindigenous Aquatic Species database · Maximum recorded · Observed in the wild · checked 2026-08-29

What this kind of claim needs: size a well-kept specimen reaches — no external source is required, provided AquariumHQ shows its reasoning. A documented maximum is held and the catalogue's typical adult range is stated separately, with the relationship between them recorded rather than collapsed. The largest recorded specimen exceeds the typical adult size by a normal margin. Most individuals will not approach it, and it is not a planning figure.

What would improve this: Corroborate against a second, independent source.

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.

temperatureAquariumHQ'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 would improve this: Go and read a source. This is reachable and has not been reached.

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 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 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 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.
Scientific and trade namesThis species has been published under more than one accepted name.
Wild conditions and aquarium recommendationsThe water band on this page is an AquariumHQ position with a stated reason, not a measurement of a river.
Why fish size figures disagreeA documented maximum and a typical adult size are both held for this species, and they are different quantities.
How aquarium species get into the wildThis species has a documented introduction outside its native range, with the route recorded.
What a legal restriction on a species actually meansAquariumHQ holds a structured legal status for this species, and possession, sale, import and release are four separate questions.

Island apple snail

Quick profile

What keeping this species involves

Identity and names

Adult size and growth

Water and tank requirements

Where these figures come from

Group size and social behaviour

Behaviour

Telling males from females

Feeding

Breeding

Tankmates and compatibility

Welfare considerations

Problems to watch for

Where it comes from

What the checklists say

Legal status and responsible practice

Where this species has been introduced, and what followed

Southeastern United States

What has been established

Europe — Spain from 2009, also recorded in Israel and Norway

What has been established

EU

US

GB

Evidence

Why we say this

Guides relevant to this species