- Common name
- Amazon leaffish
- Scientific name
- Monocirrhus polyacanthus
- Category
- Freshwater fish
- Group
- Leaf fishes and ambush predators
- Environment
- Freshwater aquarium
- Origin
- Amazon basin in Peru, Brazil, Bolivia, Colombia and Venezuela
- Care level
- Advanced
- Adult size
- Up to 8 cm standard length
- Expected lifespan
- A dependable species-specific maximum was not located; plan for 5–8 years of specialist ambush-predator care.
- Minimum housing
- At least 120 L for one adult or a proven compatible pair, with dense visual cover and clear strike lanes
- Temperature
- 22–25 °C
- pH
- 5.0–6.0
- Hardness / minerals
- 5–8 °dGH (about 89–143 mg/L as CaCO3)
- Salinity
- Freshwater; no routine salt addition
- Lighting
- Subdued
- Placement / zone
- Hovers in middle and lower water near cover.
- Filtration
- Use mature biological filtration sized for the complete adult amazon leaffish group, with guarded intakes and accessible mechanical capture. Keep flow gentle, with leaf-like cover and calm stalking zones where the fish lives, and maintain undetectable ammonia and nitrite.
- Aeration
- Maintain reliable surface agitation and oxygen exchange at all times. Increase aeration during warm weather, medication, transport recovery, heavy feeding or any sign of rapid breathing.
- Maintenance
- Perform regular matched-water changes guided by nitrate and waste, remove uneaten food and trapped detritus, clean mechanical media without disrupting the biofilter, and record feeding, body condition, respiration and aggression.
Identity and search names
Single-profile scope for Monocirrhus polyacanthus. Preserve permanent AquaNexus ID 1227, slug amazon-leaffish and route /species/amazon-leaffish/; retain former combinations, locality labels, domestic-form names and trade names only as searchable aliases.
Search names: Amazon leaf fish, South American leaffish, Leaffish
Environment and housing
Leaf litter, broad leaves, fine branches, subdued light and open strike lanes.
Social structure: Usually best singly or as a proven compatible pair; conspecific aggression and cannibalism risk must be monitored.
Feeding and nutrition
Feeding ecology: Specialist piscivore; captive feeding requires a planned transition to safe non-live foods where possible
Feeding routine: Offer small measured meals daily while transitioning to safe frozen or prepared carnivore foods; avoid routine feeder-fish dependence
Breeding, reproduction or spread
Eggs are attached to the underside of a broad leaf or comparable surface; clutches of up to roughly 300 have been reported
Detailed care and app-ready planning
- Identity scope
- Single-profile scope for Monocirrhus polyacanthus. Preserve permanent AquaNexus ID 1227, slug amazon-leaffish and route /species/amazon-leaffish/; retain former combinations, locality labels, domestic-form names and trade names only as searchable aliases.
- Adult size and space
- Expected adult size: Up to 8 cm standard length. Minimum permanent housing: At least 120 L for one adult or a proven compatible pair, with dense visual cover and clear strike lanes. Plan around adult dimensions, activity, social structure, aggression, oxygen demand and waste production rather than sale size.
- Social structure
- Usually best singly or as a proven compatible pair; conspecific aggression and cannibalism risk must be monitored.
- Swimming zone or placement
- Primary zone: Hovers in middle and lower water near cover.. Keep that zone usable for movement, feeding, refuge and escape.
- Feeding ecology
- Specialist piscivore; captive feeding requires a planned transition to safe non-live foods where possible
- Feeding plan
- Offer small measured meals daily while transitioning to safe frozen or prepared carnivore foods; avoid routine feeder-fish dependence
- Water stability
- Maintain 22–25 °C; pH 5.0–6.0; hardness or minerals: 5–8 °dGH (about 89–143 mg/L as CaCO3); salinity: Freshwater; no routine salt addition. Stability, oxygenation and nitrogen-cycle control matter more than chasing one exact value.
- Habitat structure
- Leaf litter, broad leaves, fine branches, subdued light and open strike lanes.
- Compatibility plan
- Species-focused housing or calm fish too large to swallow and not aggressive at feeding
- Breeding or reproduction plan
- Eggs are attached to the underside of a broad leaf or comparable surface; clutches of up to roughly 300 have been reported Parental care: The male guards and fans the clutch until hatching; fry then require minute live foods and careful separation.
- Quarantine
- Quarantine new livestock in a separate cycled system for at least 30 days. Observe appetite, respiration, waste, skin, fins and behaviour; use dedicated equipment and never add transport water to the established aquarium.
- Welfare checks
- Maintain the stated adult space and social structure, verify feeding, and intervene early when injury, exclusion, weight loss, abnormal respiration or altered behaviour appears. This camouflage ambush predator can swallow unexpectedly large fish. Routine feeder-fish use creates parasite, disease and nutritional risks.
- Biosecurity and release
- Never release fish, fry, eggs, aquarium water, sediment, plants or live foods into drains, dams or natural waterways. Confirm current Australian import conditions and South Australian possession, trade and movement rules before acquisition or transfer.
- Main risk
- This camouflage ambush predator can swallow unexpectedly large fish. Routine feeder-fish use creates parasite, disease and nutritional risks.
- Adult projected load
- Project biological load from the full adult amazon leaffish group, adult body mass, feeding pattern, activity and social requirement rather than juvenile sale size. Live or frozen animal foods and a predator’s feeding waste create a moderate load despite low cruising activity.
- Filtration
- Use mature biological filtration sized for the complete adult amazon leaffish group, with guarded intakes and accessible mechanical capture. Keep flow gentle, with leaf-like cover and calm stalking zones where the fish lives, and maintain undetectable ammonia and nitrite.
- Aeration
- Maintain reliable surface agitation and oxygen exchange at all times. Increase aeration during warm weather, medication, transport recovery, heavy feeding or any sign of rapid breathing.
- Maintenance
- Perform regular matched-water changes guided by nitrate and waste, remove uneaten food and trapped detritus, clean mechanical media without disrupting the biofilter, and record feeding, body condition, respiration and aggression.
- Overridable warnings
- Non-overridable: do not accept persistent ammonia or nitrite, oxygen distress, starvation, chronic aggression or inadequate adult space. Different equipment, stocking or maintenance methods may be used only when measured water quality and adult welfare remain equivalent or better. Small fish are prey, and an animal that will not accept a safe complete diet may require a long-term live-food biosecurity plan.
Compatibility, welfare and risk
Compatibility: Species-focused housing or calm fish too large to swallow and not aggressive at feeding
Welfare: Maintain the stated adult space and social structure, verify feeding, and intervene early when injury, exclusion, weight loss, abnormal respiration or altered behaviour appears. This camouflage ambush predator can swallow unexpectedly large fish. Routine feeder-fish use creates parasite, disease and nutritional risks.
Main warning: This camouflage ambush predator can swallow unexpectedly large fish. Routine feeder-fish use creates parasite, disease and nutritional risks.
Biosecurity and release
Never release fish, fry, eggs, aquarium water, sediment, plants or live foods into drains, dams or natural waterways. Confirm current Australian import conditions and South Australian possession, trade and movement rules before acquisition or transfer.