- Common name
- Amazon frogbit
- Scientific name
- Hydrocharis laevigata
- Category
- Aquarium plant
- Group
- Floating aquatic plants
- Environment
- Freshwater surface-floating plant
- Origin
- Native from Mexico through tropical America; introduced in parts of Australia and other regions
- Care level
- Easy biologically, but legal and biosecurity restrictions can make possession inappropriate
- Adult size
- Leaves up to about 4 cm long; rosette spread and root length vary with conditions
- Expected lifespan
- Perennial aquatic plant; individual leaves and daughter rosettes are continually replaced
- Minimum housing
- No fixed aquarium volume; maintain open surface area and prevent complete coverage
- Temperature
- Unknown — no dependable species-specific aquarium range found
- pH
- Unknown — no dependable species-specific aquarium range found
- Hardness / minerals
- Unknown — no dependable numeric GH or KH range found
- Salinity
- Freshwater
- Lighting
- Moderate to high light above an open, humid surface
- Placement / zone
- Floating at the water surface with leaf tops kept dry
- Filtration
- Use gentle intake guards and a clear equipment zone so roots are not shredded or pulled into filters. Thin the mat before it blocks surface exchange, light or feeding access; filtration does not replace biomass removal.
- Aeration
- Maintain oxygen exchange in an open section of the surface without repeatedly wetting or submerging leaf tops. Position outlets so circulation reaches below the mat while the floating rosettes remain intact.
- Maintenance
- Thin and securely dispose of excess plants, remove yellow or rotting leaves, clear filter guards, inspect for hitchhikers and preserve an open surface zone for gas exchange and animal access.
Identity and search names
Use for Hydrocharis laevigata only. Do not apply automatically to native Australian Hydrocharis species or unrelated frogbit.
Search names: Limnobium laevigatum, South American spongeplant, West Indian spongeplant, Frogbit
Environment and housing
Still or slow freshwater with an open surface. Keep leaf tops dry and prevent strong splashing or condensation damage.
Social structure: Floating clonal rosettes linked by daughter growth; no animal social structure applies. Colony density must be controlled before the surface closes.
Feeding and nutrition
Feeding ecology: Water-column nutrients and atmospheric carbon dioxide
Feeding routine: Do not fertilise solely to accelerate spread. Maintain balanced livestock-safe nutrients and remove excess biomass when growth outpaces the system.
Breeding, reproduction or spread
Spreads readily by vegetative daughter plants and can also reproduce sexually. Remove excess growth before it escapes.
Detailed care and app-ready planning
- Identity scope
- Use for Hydrocharis laevigata only. Do not apply automatically to native Australian Hydrocharis species or unrelated frogbit.
- Adult size and space
- Leaves may reach about 4 cm; colonies can cover the surface rapidly through daughter rosettes.
- Social structure
- Floating clonal rosettes linked by daughter growth; no animal social structure applies. Colony density must be controlled before the surface closes.
- Swimming zone or placement
- Floating surface layer with roots hanging through upper water; no swimming zone applies.
- Feeding ecology
- Uses atmospheric carbon dioxide and water-column nutrients while floating at the surface.
- Feeding plan
- Do not fertilise solely to accelerate spread. Maintain balanced livestock-safe nutrients and remove excess biomass when growth outpaces the system.
- Water stability
- Avoid sudden temperature changes, strong surface turbulence and persistent wetting of leaf tops.
- Habitat structure
- Open, relatively calm freshwater surface with leaf tops kept dry, roots protected from intakes and a permanent clear zone for gas exchange and animal access.
- Compatibility plan
- Thin regularly to preserve light, oxygen exchange and feeding access for fish. Herbivorous or surface-active animals may damage roots.
- Breeding or reproduction plan
- Vegetative division is easy, but propagation must not occur where possession or trade is restricted.
- Quarantine
- Inspect for snails, eggs, algae, hydra and chemical residues. Treat all removed material as potentially viable.
- Welfare checks
- Check leaf colour, root integrity, wet or rotting crowns, pest load and excessive surface coverage.
- Biosecurity and release
- Never place this plant or fragments in drains, compost near waterways, dams or outdoor ponds. Check state weed law before possession, sale or disposal.
- Main risk
- Escape and formation of invasive surface mats.
- Adult projected load
- The main projected load is rapidly expanding surface coverage, root biomass, nutrient uptake and decaying plant material. A small starter portion can become a system-wide light, oxygen and access problem.
- Filtration
- Use gentle intake guards and a clear equipment zone so roots are not shredded or pulled into filters. Thin the mat before it blocks surface exchange, light or feeding access; filtration does not replace biomass removal.
- Aeration
- Maintain oxygen exchange in an open section of the surface without repeatedly wetting or submerging leaf tops. Position outlets so circulation reaches below the mat while the floating rosettes remain intact.
- Maintenance
- Thin and securely dispose of excess plants, remove yellow or rotting leaves, clear filter guards, inspect for hitchhikers and preserve an open surface zone for gas exchange and animal access.
- Overridable warnings
- Non-overridable: do not allow complete surface closure or release viable plants, daughter rosettes, fragments or aquarium water. A knowledgeable user may alter thinning frequency or outlet layout only while open-surface access, oxygen exchange and lawful containment remain protected.
- Identity
- The accepted botanical name is Hydrocharis laevigata. Limnobium laevigatum remains widely used in aquarium and weed literature.
- Environment
- Still or slow freshwater with an open surface. Keep leaf tops dry and prevent strong splashing or condensation damage.
- Feeding
- Takes nutrients from the water column and carbon dioxide from the air. Nutrient demand rises rapidly when colonies expand.
- Breeding
- Spreads readily by vegetative daughter plants and can also reproduce sexually. Remove excess growth before it escapes.
- Adult size and space
- Leaves may reach about 4 cm; colonies can cover the surface rapidly through daughter rosettes.
- Growth Rate
- Fast under warm bright nutrient-rich conditions.
- Lighting Plan
- Provide moderate to high overhead light while preventing heat damage and keeping leaf tops dry.
- Carbon Plan
- Uses atmospheric CO2; injected aquarium CO2 is not required for floating leaves.
- Nutrient Plan
- Remove excess biomass rather than escalating fertiliser when it begins dominating the surface.
- Substrate Plan
- No substrate; roots hang freely in the water column.
- Propagation plan
- Vegetative division is easy, but propagation must not occur where possession or trade is restricted.
- Biosecurity and release
- Never place this plant or fragments in drains, compost near waterways, dams or outdoor ponds. Check state weed law before possession, sale or disposal.
Compatibility, welfare and risk
Compatibility: Can shade submerged plants and restrict gas exchange if allowed to cover the whole surface
Welfare: Check leaf colour, root integrity, wet or rotting crowns, pest load and excessive surface coverage.
Main warning: A high-risk invasive floating plant. It is prohibited matter in New South Wales and must not be sold, moved or released where restricted.
Biosecurity and release
Never place this plant or fragments in drains, compost near waterways, dams or outdoor ponds. Check state weed law before possession, sale or disposal.