Home / Fishes / Damselfish and dottybacks / Amazon leaffish
No federal permit to keepAmazon leaffish
Monocirrhus polyacanthus
Fishes › Damselfish and dottybacks (Ovalentaria) › Polycentridae (Leaf fish)
The Amazon leaffish (Monocirrhus polyacanthus), or South American leaffish, is a species of fish belonging to the family Polycentridae.
Care at a glance
Species-specific aquarium care
- Tank: At least 24 in long and 12 in front to back for one adult (adults commonly reach about 3.1 in / 8 cm).
- Water: Freshwater.
- Temperature: 72–77°F (range recorded for this species).
- pH: 5–6.
- Hardness: 5–8 dGH.
- Layout: Uses both the bottom and open water: give open swimming space plus cover near the substrate.
- Diet: A predator: feed meaty foods sized to its mouth (frozen fish, shrimp, worms); it will eat tankmates that fit in its mouth. FishBase classes it as a carnivore.
Calculated from this species' own FishBase record: tank size from its typical adult length and swimming zone, water values from its recorded ranges. The group guide below fills in general care.
Care guide
Species care notes
- Tank: a base of at least 30 × 12 in (roughly 18 US gallons); space needed is rated “modest tank”.
- Water: soft, acidic water, 73–84 °F, pH 5–6.8, 1–10 dGH.
- Difficulty: Beginner (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “Soft acidic water is essential.”
- Diet: “Carnivorous and will only accept live food.”
- Tankmates: “A species tank is highly preferable although M.”
- Breeding: “Can be achieved in captivity.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
Leaf fish
Applies to most species in this group. Habitat: These camouflaged ambush predators inhabit sheltered South American waters and, for Polycentropsis abbreviata, vegetated African pools, swamps and slow rivers. [fg313-amazon, fg313-african, fg313-guyana]. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- For Monocirrhus polyacanthus, the published aquarium size is 75 × 30 × 30 cm.
- For Polycentropsis abbreviata, use at least 60 × 38 × 30 cm; larger quarters are needed for a group.
- Provide subdued lighting, floating plants, dense broad-leaved planting and wood shelters; keep flow gentle for P. abbreviata.
- For Polycentrus schomburgkii, provide dense plants and multiple caves; its profile permits two in 10 US gallons, a species-specific figure rather than a family minimum.
- Maintain soft acidic water: Monocirrhus pH 5–6.5 and hardness below 8 dGH; P. abbreviata pH 6–6.5 and 1–10 dGH.
Diet
- Live river or ghost shrimp for Monocirrhus and Polycentrus.
- Small earthworms for all three listed species.
- Live bloodworms for Polycentropsis.
- Live brine shrimp for Polycentrus.
Social life
- A species aquarium avoids predation and feeding competition. P. abbreviata can form small groups with enough space; breeding Polycentrus males guard eggs and the female should be separated.
Health watch
- Loss of condition when live-food specialists fail to accept available food.
- Water-quality stress, particularly in young leaf fish.
- External parasites and opportunistic bacterial infections are general aquarium risks; family-specific incidence is undocumented.
Understanding the animal
About this animal
About this animal
It is found in the Amazon basin in Bolivia, Brazil, Colombia, Peru and Venezuela, where it inhabits edges of rivers and lakes, and streams. It is generally a low-density species that lives in slow-moving or essentially stagnant waters in areas with plant debris.
Quoted from the Wikipedia article “Amazon leaffish” (CC BY-SA 4.0) 174
In the wild
In the wild
From this species’ own FishBase record (habitat, bottom type, water and breeding data), not its family. Good care copies these conditions.1
| Where it lives | Lives in freshwater. Uses both the bottom and open water. |
| Water it lives in | Freshwater, 72–77 °F (22–25 °C), pH 5–6, hardness 5–8 dH. |
| Climate | Tropical climate. |
| Wild diet | Hunting macrofauna (predator). |
| Behavior to plan for | Breeding: clutch tenders. |
What this means for care
- Keep water within its wild range, 72–77 °F.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 90°F (up to 94°F in the hottest sampled areas) |
| Cool-season lows | about 71°F (down to 66°F in the coldest sampled areas) |
| Average temperature | 79–81°F across sampled records |
| Relative humidity | 81–85% on average (driest month about 78%) |
| Rainfall | about 2388 mm a year |
Measured at 149 wild occurrence records sampled against WorldClim 2.1 climate data (1970–2000 averages). Air conditions in the range are ecological context, not enclosure settings: microhabitats such as burrows, leaf litter or basking rocks can be cooler, warmer or more humid.
From the sources
From the sources
Quoted from the matching sections of reputable sources for this exact species. Specialist databases are used first; Wikipedia (community-edited, CC BY-SA 4.0) only fills gaps. Other sources are short credited quotes.
| Overview | The Amazon leaffish (Monocirrhus polyacanthus), or South American leaffish, is a species of fish belonging to the family Polycentridae. It is found in the Amazon basin in Bolivia, Brazil, Colombia, Peru and Venezuela, where it inhabits edges of rivers and lakes, and streams. It is generally a low-density species that lives in slow-moving or essentially stagnant waters in areas with plant debris. Amazon leaffish are sometimes kept in aquariums, but they require acidic water, low light and live prey. — Wikipedia (community-edited) |
| Where it lives | Home ranges Population dynamics Growth parameters Max. ages / sizes Length-weight rel. Length-frequencies Mass conversion Recruitment Abundance Life cycle Reproduction Maturity Maturity/Gills rel. — FishBase |
| Behavior | The Amazon leaffish is highly predatory, feeding on small invertebrates (aquatic insects like mayfly nymphs and crustaceans like shrimp) and fish (especially Characids and Lebiasinids). Small Amazon leaffish mostly feed on invertebrates, while larger individuals mainly feed on fish. The prey fish are swallowed whole and they are often quite large compared to the size of the leaffish. — Wikipedia (community-edited) |
| Appearance and size | The Amazon leaffish reaches a maximum standard length of 8 cm, and a total length of 10 cm. As suggested by its common name, it closely resembles a dead leaf. The flattened body and filament at the tip of the lower jaw (resembling a stalk) further enhances its similarity to a leaf. — Wikipedia (community-edited) |
Data and studies
The numbers
The numbers
Each bar is what one source reports. Where several sources weigh in, the dashed gold band marks their average.
Adult length
Maximum recorded length. Measured as standard length (snout to the base of the tail, not counting the tail fin). Fish in home aquariums often stay smaller than wild records.
Water temperature
Range the species tolerates in nature; aim for the middle.
Minimum tank footprint
Seriously Fish recommends a tank base of at least 30 × 12 in (about 18 US gallons).
Veterinary & husbandry research
Veterinary & husbandry research
- Detection of betanodaviruses in apparently healthy aquarium fishes and invertebrates Gomez DK et al., Journal of veterinary science 2006
Peer-reviewed papers that mention this species alongside captivity, zoos, veterinary care or aquaculture. Some cover several species or mention it only in passing, so check the abstract. 170
Sources for this sheet
- FishBase (Froese & Pauly, eds.), version 24.07 Peer-reviewed researchThe global scientific database on fishes, maintained by a consortium of research institutions; every value is referenced.
- Seriously Fish species profiles Experienced keeper or breederLong-running aquarium reference written and peer-checked by experienced fishkeepers and ichthyologists; each profile covers habitat, tank size, water, diet, behaviour and breeding.
- Practical Fishkeeping: Predators — The leaf fish Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Seriously Fish: Polycentropsis abbreviata Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Aquatic Community: Guyana Leaffish — Polycentrus schomburgkii Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- UF/IFAS: Fish Health Management in Recirculating Aquaculture Systems, Part 2: Pathogens Zoo, university or veterinaryAdded in the 2026 source-checked care-guide review.
- Wikipedia (species article) Community referenceFree encyclopedia; useful overviews with their own citations. Intro text is quoted under CC BY-SA 4.0.
- PubMed (U.S. National Library of Medicine) Peer-reviewed researchIndex of peer-reviewed veterinary, zoo and husbandry research.
- iNaturalist (captive observations) Community referenceCommunity observation platform run by the California Academy of Sciences and National Geographic; observations marked captive show animals living in homes, zoos and aquariums.
